diff --git a/.gitignore b/.gitignore
index 67b8271..b852c3a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,9 +2,8 @@
 .Rhistory
 .RData
 .Ruserdata
-*.sqlite
-*.sqlite-journal
-*.rds
+.Rprofile
+
 .vscode
+
 docs
-pkgdown
diff --git a/.lintr b/.lintr
index d2d542e..767a8e8 100644
--- a/.lintr
+++ b/.lintr
@@ -1,6 +1,6 @@
 linters: linters_with_defaults(
-  line_length_linter(120),
-  object_usage_linter = NULL,
-  indentation_linter = NULL,
-  trailing_whitespace_linter = NULL
+    line_length_linter(120),
+    object_usage_linter = NULL,
+    indentation_linter = NULL,
+    trailing_whitespace_linter = NULL
   )
diff --git a/DESCRIPTION b/DESCRIPTION
index a12e282..f8877f8 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,22 +1,29 @@
 Package: dv.loader
 Type: Package
-Title: Data loading module 
-Version: 2.0.0
+Title: Data Loader for DaVinci Modular Applications
+Version: 3.0.0
 Authors@R: c(
-        person( "Boehringer-Ingelheim Pharma GmbH & Co.KG", role = c("cph", "fnd")),
-        person( given = "Ming", family = "Yang", role = c("aut", "cre"), email = "ming.yang.ext@boehringer-ingelheim.com"),
-        person( given = "Steven", family = "Brooks", role = "aut", email = "steven.brooks@boehringer-ingelheim.com"),
-        person( given = "Sorin", family = "Voicu", role = "aut", email = "sorin.voicu.ext@boehringer-ingelheim.com")
+        person("Boehringer-Ingelheim Pharma GmbH & Co.KG", role = c("cph", "fnd")),
+        person("Ming", "Yang", email = "ming.yang.ext@boehringer-ingelheim.com", role = c("aut", "cre")),
+        person("Steven", "Brooks", email = "steven.brooks@boehringer-ingelheim.com", role = "aut"),
+        person("Sorin", "Voicu", email = "sorin.voicu.ext@boehringer-ingelheim.com", role = "aut")
     )
-Description: This is a module for loading .RDS / .sas7bdat data files from a network file storage environment. It also allows loading data locally.
+Description: dv.loader offers a streamlined method for importing multiple data files in R, 
+    tailored for seamless integration with DaVinci modular applications.
 License: Apache License (>= 2)
 Encoding: UTF-8
 LazyData: true
-Depends: R (>= 3.5.0)
-Imports: haven
+Depends: R (>= 4.0.0)
+Imports:
+    checkmate (>= 2.3.2),
+    haven (>= 2.5.4),
+    lifecycle (>= 1.0.4)
 Suggests: 
-    testthat,
-    knitr,
-    rmarkdown
-RoxygenNote: 7.3.0
+    knitr (>= 1.48),
+    pharmaverseadam (>= 1.0.0),
+    pharmaversesdtm (>= 1.0.0),
+    rmarkdown (>= 2.38),
+    testthat (>= 3.2.1.1)
+RoxygenNote: 7.3.2
 VignetteBuilder: knitr
+Config/testthat/edition: 3
diff --git a/NAMESPACE b/NAMESPACE
index 79ce8a0..595a91d 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -1,5 +1,7 @@
 # Generated by roxygen2: do not edit by hand
 
-export(get_cre_path)
-export(get_nfs_path)
 export(load_data)
+export(load_rds)
+export(load_sas)
+export(load_xpt)
+importFrom(lifecycle,deprecate_warn)
diff --git a/NEWS.md b/NEWS.md
index a5c5124..63ce9ea 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,3 +1,8 @@
+# dv.loader 3.0.0
+
+- Introduced a new set of functions `load_rds()`, `load_sas()`, and `load_xpt()`.
+- Deprecated the function `load_data()`.
+
 # dv.loader 2.0.0
 
 - GitHub release with QC report
diff --git a/R/dvloader.R b/R/dvloader.R
deleted file mode 100644
index a36a7b9..0000000
--- a/R/dvloader.R
+++ /dev/null
@@ -1,61 +0,0 @@
-#' gets the NFS base path from an env var
-#' It assumes there is an env var
-#' called RXD_DATA which holds the path suffix.
-#' @return the NFS base path
-#' @export
-get_nfs_path <- function() {
-  base_path <- Sys.getenv("RXD_DATA")
-  # check that RXD_DATA is set
-  if (base_path == "") {
-    stop("Usage: get_nfs_path: RXD_DATA must be set")
-  }
-  return(base_path)
-}
-
-#' gets the NFS base path from an env var
-#' alias for get_nfs_path to maintain backwards compatibility
-#' @export
-get_cre_path <- get_nfs_path
-
-#' Loads data into memory based on study directory and one or more file_names.
-#' @param sub_dir A relative directory/folder that will be appended to a base path defined by `Sys.getenv("RXD_DATA")`.
-#' If the argument is left as NULL, the function will load data from the working directory `getwd()`.
-#' @param file_names Study file or file_names name(s) - can be a vector of strings.
-#' This is the only required argument.
-#' @param use_wd for "use working directory" - a flag used when importing local files
-#' not on NFS - default value is FALSE
-#' @param prefer_sas if set to TRUE, imports sas7bdat files first before looking for
-#' RDS files (the opposite of default behavior)
-#' @return a list of dataframes
-#' @export
-#' @examples
-#' \dontrun{
-#' test_data_path <- "../inst/extdata/"
-#' data_list <- load_data(
-#'   sub_dir = test_data_path,
-#'   file_names = "dummyads2",
-#'   use_wd = TRUE
-#' )
-#' }
-load_data <- function(sub_dir = NULL, file_names, use_wd = FALSE, prefer_sas = FALSE) {
-  if (is.null(file_names)) {
-    stop("Usage: load_data: file_names: Must supply at least one file name")
-  }
-
-  study_path <- "" # will be built using args
-
-  if (is.null(sub_dir)) {
-    study_path <- getwd()
-  } else {
-    if (use_wd) {
-      study_path <- file.path(getwd(), sub_dir)
-    } else {
-      study_path <- file.path(get_cre_path(), sub_dir)
-    }
-  }
-
-  # create the output
-  data_list <- create_data_list(study_path, file_names, prefer_sas) # nolint
-
-  return(data_list)
-}
diff --git a/R/load_data.R b/R/load_data.R
new file mode 100644
index 0000000..0d4194f
--- /dev/null
+++ b/R/load_data.R
@@ -0,0 +1,146 @@
+#' Loads data into memory based on study directory and one or more file_names.
+#' @param sub_dir A relative directory/folder that will be appended to a base path defined by `Sys.getenv("RXD_DATA")`.
+#' If the argument is left as NULL, the function will load data from the working directory `getwd()`.
+#' @param file_names Study file or file_names name(s) - can be a vector of strings.
+#' This is the only required argument.
+#' @param use_wd for "use working directory" - a flag used when importing local files
+#' not on NFS - default value is FALSE
+#' @param prefer_sas if set to TRUE, imports sas7bdat files first before looking for
+#' RDS files (the opposite of default behavior)
+#' @return a list of dataframes
+#' @export
+#' @examples
+#' \dontrun{
+#' test_data_path <- "../inst/extdata/"
+#' data_list <- load_data(
+#'   sub_dir = test_data_path,
+#'   file_names = "dummyads2",
+#'   use_wd = TRUE
+#' )
+#' }
+#' @export
+#' @importFrom lifecycle deprecate_warn
+load_data <- function(sub_dir = NULL, file_names, use_wd = FALSE, prefer_sas = FALSE) {
+  lifecycle::deprecate_warn("3.0.0", "load_data()", "read_data()")
+  
+  if (is.null(file_names)) {
+    stop("Usage: load_data: file_names: Must supply at least one file name")
+  }
+  
+  study_path <- "" # will be built using args
+  
+  if (is.null(sub_dir)) {
+    study_path <- getwd()
+  } else {
+    if (use_wd) {
+      study_path <- file.path(getwd(), sub_dir)
+    } else {
+      study_path <- file.path(get_cre_path(), sub_dir)
+    }
+  }
+  
+  # create the output
+  data_list <- create_data_list(study_path, file_names, prefer_sas) # nolint
+  
+  return(data_list)
+}
+
+#' gets the NFS base path from an env var
+#' It assumes there is an env var
+#' called RXD_DATA which holds the path suffix.
+#' @return the NFS base path
+get_nfs_path <- function() {
+  base_path <- Sys.getenv("RXD_DATA")
+  # check that RXD_DATA is set
+  if (base_path == "") {
+    stop("Usage: get_nfs_path: RXD_DATA must be set")
+  }
+  return(base_path)
+}
+
+#' gets the NFS base path from an env var
+#' alias for get_nfs_path to maintain backwards compatibility
+get_cre_path <- get_nfs_path
+
+
+#' For each file name provided, reads in the first matching file and its meta data/attributes.
+#' Preference is given to RDS because its faster
+#' @param file_path the folder where the files are
+#' @param file_names CDISC names for the files
+#' @param prefer_sas if TRUE, imports .sas7bdat files first instead of .RDS files
+#' @return returns a list of dataframes with metadata as an attribute on each dataframe
+create_data_list <- function(file_path, file_names, prefer_sas) {
+  data_list <- lapply(file_names, function(x) {
+    extensions <- c("", ".rds", ".sas7bdat")
+    if (prefer_sas) {
+      extensions <- c("", ".sas7bdat", ".rds")
+    }
+    
+    file_name_to_load <- NULL
+    
+    candidates <- list.files(file_path)
+    uppercase_candidates <- Map(toupper, candidates)
+    
+    for (ext in extensions) {
+      # Case insensitive file name match
+      uppercase_file_name <- toupper(paste0(x, ext))
+      
+      match_count <- sum(uppercase_candidates == uppercase_file_name)
+      if (match_count > 1) {
+        stop(paste("create_data_list(): More than one case-insensitive file name match for", file_path, x))
+      }
+      
+      index <- match(uppercase_file_name, uppercase_candidates)
+      if (!is.na(index)) {
+        file_name_to_load <- candidates[[index]]
+        break
+      }
+    }
+    
+    if (is.null(file_name_to_load)) {
+      stop(paste("create_data_list(): No RDS or SAS files found for", file_path, x))
+    }
+    
+    output <- read_file(file_path, file_name_to_load)
+    
+    return(output)
+  })
+  
+  names(data_list) <- file_names
+  
+  return(data_list)
+}
+
+
+#' Reads RDS/SAS file and metadatas from first 6 items from file.info() its file path
+#' @param file_path a path to a file
+#' @param file_name name of a file
+#' @return a data object with an extra attribute of metadata
+read_file <- function(file_path, file_name) {
+  ext <- tools::file_ext(file_name)
+  
+  if (!(toupper(ext) %in% c("RDS", "SAS7BDAT"))) {
+    stop("Usage error: read_file: file_name: file must either be RDS or SAS7BDAT.")
+  }
+  
+  is_rds <- toupper(ext) == "RDS"
+  
+  file <- file.path(file_path, file_name)
+  file_name <- tools::file_path_sans_ext(file_name)
+  
+  # grab file info
+  meta <- file.info(file)[1L:6L]
+  meta[["path"]] <- row.names(meta)
+  meta[["file_name"]] <- file_name
+  meta <- data.frame(meta, stringsAsFactors = FALSE)
+  row.names(meta) <- NULL
+  
+  if (is_rds) {
+    out <- readRDS(file)
+  } else {
+    out <- haven::read_sas(file)
+  }
+  attr(out, "meta") <- meta
+  
+  return(out)
+}
diff --git a/R/load_rds.R b/R/load_rds.R
new file mode 100644
index 0000000..a1a9008
--- /dev/null
+++ b/R/load_rds.R
@@ -0,0 +1,47 @@
+#' Load RDS files
+#'
+#' This function loads RDS files via readRDS() and returns a list of data frames.
+#'
+#' @param files A character vector of file paths to RDS files.
+#' @return A list of data frames, each containing the data from an RDS file.
+#' @examples
+#' # Create temporary directory and files
+#' temp_dir <- tempdir()
+#' adsl_rds_file <- file.path(temp_dir, "adsl.rds")
+#' adae_rds_file <- file.path(temp_dir, "adae.rds")
+#' 
+#' # Write example data to RDS files
+#' saveRDS(pharmaverseadam::adsl, adsl_rds_file)
+#' saveRDS(pharmaverseadam::adae, adae_rds_file)
+#' 
+#' # Load RDS files
+#' rds_data_list <- load_rds(c(adsl_rds_file, adae_rds_file))
+#' 
+#' # Clean up
+#' unlink(c(adsl_rds_file, adae_rds_file))
+#' @export
+load_rds <- function(files) {
+  # Check if files is a character vector
+  checkmate::assert_character(files)
+  
+  # Read each file and add metadata
+  data_list <- lapply(files, function(file) {
+    # Check if file exists
+    checkmate::assert_file_exists(file)
+    # Check if file is an RDS file
+    check_file_ext(file, extension = "rds")
+    
+    # Read RDS file
+    data <- readRDS(file)
+    
+    # Get file info and add to data as an attribute
+    attr(data, "meta") <- file_info(file)
+    
+    return(data)
+  })
+  
+  # Set names of data_list to the file names
+  names(data_list) <- basename(files)
+
+  return(data_list)
+}
diff --git a/R/load_sas.R b/R/load_sas.R
new file mode 100644
index 0000000..01c7a4c
--- /dev/null
+++ b/R/load_sas.R
@@ -0,0 +1,46 @@
+#' Load SAS files
+#'
+#' This function loads SAS files via haven::read_sas() and returns a list of data frames.
+#'
+#' @param files A character vector of file paths to SAS files.
+#' @return A list of data frames, each containing the data from a SAS file.
+#' @examples
+#' # Create temporary directory and files
+#' temp_dir <- tempdir()
+#' adsl_sas_file <- file.path(temp_dir, "adsl.sas7bdat")
+#' adae_sas_file <- file.path(temp_dir, "adae.sas7bdat")
+#' 
+#' # Write example data to SAS files
+#' haven::write_sas(pharmaverseadam::adsl, adsl_sas_file)
+#' haven::write_sas(pharmaverseadam::adae, adae_sas_file)
+#' 
+#' # Load SAS files
+#' sas_data_list <- load_sas(c(adsl_sas_file, adae_sas_file))
+#' 
+#' # Clean up
+#' unlink(c(adsl_sas_file, adae_sas_file))
+#' @export
+load_sas <- function(files) {
+  # Check if files is a character vector
+  checkmate::assert_character(files)
+  
+  # Read each file and add metadata
+  data_list <- lapply(files, function(file) {
+    # Check if file exists
+    checkmate::assert_file_exists(file)
+    # Check if file is a SAS file
+    check_file_ext(file, extension = "sas7bdat")
+        
+    # Read SAS file
+    data <- haven::read_sas(file)
+    
+    # Get file info and add to data as an attribute
+    attr(data, "meta") <- file_info(file)
+    
+    return(data)
+  })
+  
+  # Set names of data_list to the file names
+  names(data_list) <- basename(files)
+  return(data_list)
+}
diff --git a/R/load_xpt.R b/R/load_xpt.R
new file mode 100644
index 0000000..debf34b
--- /dev/null
+++ b/R/load_xpt.R
@@ -0,0 +1,47 @@
+#' Load XPT files
+#'
+#' This function loads XPT files via haven::read_xpt() and returns a list of data frames.
+#'
+#' @param files A character vector of file paths to XPT files.
+#' @return A list of data frames, each containing the data from an XPT file.
+#' @examples
+#' # Create temporary directory and files
+#' temp_dir <- tempdir()
+#' adsl_xpt_file <- file.path(temp_dir, "adsl.xpt")
+#' adae_xpt_file <- file.path(temp_dir, "adae.xpt")
+#' 
+#' # Write example data to XPT files
+#' haven::write_xpt(pharmaverseadam::adsl, adsl_xpt_file)
+#' haven::write_xpt(pharmaverseadam::adae, adae_xpt_file)
+#' 
+#' # Load XPT files
+#' xpt_data_list <- load_xpt(c(adsl_xpt_file, adae_xpt_file))
+#' 
+#' # Clean up
+#' unlink(c(adsl_xpt_file, adae_xpt_file))  
+#' @export
+load_xpt <- function(files) {
+  # Check if files is a character vector
+  checkmate::assert_character(files)
+
+  # Read each file and add metadata
+  data_list <- lapply(files, function(file) {
+    # Check if file exists
+    checkmate::assert_file_exists(file)
+    # Check if file is an XPT file
+    check_file_ext(file, extension = "xpt")
+    
+    # Read XPT file
+    data <- haven::read_xpt(file)
+    
+    # Get file info and add to data as an attribute
+    attr(data, "meta") <- file_info(file)
+    
+    return(data)
+  })
+  
+  # Set names of data_list to the file names
+  names(data_list) <- basename(files)
+
+  return(data_list)
+}
diff --git a/R/utils.R b/R/utils.R
index a3791e1..6204502 100644
--- a/R/utils.R
+++ b/R/utils.R
@@ -1,81 +1,55 @@
-#' For each file name provided, reads in the first matching file and its meta data/attributes.
-#' Preference is given to RDS because its faster
-#' @param file_path the folder where the files are
-#' @param file_names CDISC names for the files
-#' @param prefer_sas if TRUE, imports .sas7bdat files first instead of .RDS files
-#' @return returns a list of dataframes with metadata as an attribute on each dataframe
-create_data_list <- function(file_path, file_names, prefer_sas) {
-  data_list <- lapply(file_names, function(x) {
-    extensions <- c("", ".rds", ".sas7bdat")
-    if (prefer_sas) {
-      extensions <- c("", ".sas7bdat", ".rds")
-    }
-
-    file_name_to_load <- NULL
-
-    candidates <- list.files(file_path)
-    uppercase_candidates <- Map(toupper, candidates)
-
-    for (ext in extensions) {
-      # Case insensitive file name match
-      uppercase_file_name <- toupper(paste0(x, ext))
-
-      match_count <- sum(uppercase_candidates == uppercase_file_name)
-      if (match_count > 1) {
-        stop(paste("create_data_list(): More than one case-insensitive file name match for", file_path, x))
-      }
-
-      index <- match(uppercase_file_name, uppercase_candidates)
-      if (!is.na(index)) {
-        file_name_to_load <- candidates[[index]]
-        break
-      }
-    }
-
-    if (is.null(file_name_to_load)) {
-      stop(paste("create_data_list(): No RDS or SAS files found for", file_path, x))
-    }
-
-    output <- read_file(file_path, file_name_to_load)
-
-    return(output)
-  })
-
-  names(data_list) <- file_names
-
-  return(data_list)
+#' Check if a file has a specific extension (case-insensitive)
+#'
+#' This function checks if a given file has a specific extension, ignoring case.
+#'
+#' @param file A character string specifying the path to the file.
+#' @param extension A character string specifying the expected file extension (without the dot).
+#' @return A logical value: TRUE if the file has the specified extension, FALSE otherwise.
+check_file_ext <- function(file, extension) {
+  # Check input types
+  checkmate::assert_string(file)
+  checkmate::assert_string(extension)
+  
+  # Extract file extension (case-insensitive)
+  file_ext <- tolower(tools::file_ext(file))
+
+  # Check that the file extension is not empty
+  checkmate::assert_true(file_ext != "")
+
+  # Check that the file extension is one of the allowed choices
+  checkmate::assert_choice(file_ext, choices = c("rds", "sas7bdat", "xpt"))
+  
+  # Compare with the given extension (case-insensitive)
+  return(file_ext == tolower(extension))
 }
 
 
-#' Reads RDS/SAS file and metadatas from first 6 items from file.info() its file path
-#' @param file_path a path to a file
-#' @param file_name name of a file
-#' @return a data object with an extra attribute of metadata
-read_file <- function(file_path, file_name) {
-  ext <- tools::file_ext(file_name)
-
-  if (!(toupper(ext) %in% c("RDS", "SAS7BDAT"))) {
-    stop("Usage error: read_file: file_name: file must either be RDS or SAS7BDAT.")
-  }
-
-  is_rds <- toupper(ext) == "RDS"
-
-  file <- file.path(file_path, file_name)
-  file_name <- tools::file_path_sans_ext(file_name)
-
-  # grab file info
-  meta <- file.info(file)[1L:6L]
-  meta[["path"]] <- row.names(meta)
-  meta[["file_name"]] <- file_name
-  meta <- data.frame(meta, stringsAsFactors = FALSE)
-  row.names(meta) <- NULL
-
-  if (is_rds) {
-    out <- readRDS(file)
-  } else {
-    out <- haven::read_sas(file)
-  }
-  attr(out, "meta") <- meta
-
-  return(out)
+#' Extract file information based on file.info()
+#'
+#' This function extracts file information from a given file.
+#'
+#' @param file A character string specifying the path to the file.
+#' @return A list containing file information from file.info(file, extra_cols = FALSE) and the path and file name.
+file_info <- function(file) {
+  # Check if the file exists
+  checkmate::assert_file_exists(file)
+
+  # Get file information from file.info()
+  info <- file.info(file, extra_cols = FALSE)
+
+  # Get the path from the rownames
+  path <- rownames(info)
+  
+  # Check file and path are the same
+  checkmate::assert_true(file == path)
+
+  # Add path and file name
+  info[["path"]] <- path
+  info[["file_name"]] <- basename(path)
+
+  # Convert to list to remove row names
+  info <- as.list(info)
+    
+  # Return the file information as a list
+  return(info)
 }
diff --git a/README.md b/README.md
index 1199129..e3af8fa 100644
--- a/README.md
+++ b/README.md
@@ -1,30 +1,55 @@
-# Data Loading
-
-The {dv.loader} package provides a simple interface for loading data from a network file storage folder or 
-locally. It is designed to be used with `.RDS` and `.sas7bdat` file formats.
-The package provides a simple function, `load_data()`, which loads R and SAS data files into memory. 
-Loading data from SQL databases is not yet supported. The function returns a list named by the file names passed, 
-and containing data frames, along with metadata for that table. By default, the function will look for files in a
-sub-directory `sub_dir` of the base path defined by a environment variable "RXD_DATA". You can check if the base path
-is set by running `Sys.getenv("RXD_DATA")`. A single file or multiple files can be loaded at once. 
-To make the loading process faster for large datasets, it is suggested that '.sas7bdat' files are converted to 
-'.RDS' files. The function will prefer '.RDS' files over '.sas7bdat' files by default.
+# dv.loader
+
+The {dv.loader} package offers a unified approach for loading various data file formats in R. It provides a set of functions to import RDS, SAS, and XPT files, with built-in error handling and metadata extraction. The package is specifically designed to work seamlessly with the [{dv.manager}](https://boehringer-ingelheim.github.io/dv.manager/) package, facilitating the creation of modular Shiny applications within the DaVinci framework.
+
+## Key Features
+
+Below are the key features of {dv.loader}:
+
+- **Versatile File Formats**: Currently supports RDS, SAS, and XPT files.
+- **Rich Metadata**: Includes file-specific metadata for each dataset.
+- **Error Handling**: Checks for file existence and format for each file.
+- **Consistent Output**: Returns a named list of data frames and associated metadata.
+- **DaVinci Framework Integration**: Works seamlessly with other DaVinci framework packages.
 
 ## Installation
 
+While {dv.loader} is not currently available on CRAN, you can obtain the development version from GitHub using the following method:
+
 ```r
+# Install the {remotes} package if you haven't already
 if (!require("remotes")) install.packages("remotes")
+
+# Install the development version of {dv.loader}
 remotes::install_github("Boehringer-Ingelheim/dv.loader")
+
+# Check the package version
+packageVersion("dv.loader")
 ```
 
-## Basic usage
+NOTE: The legacy `load_data()` function has been deprecated in version 3.0.0 of {dv.loader}. It is strongly recommended to transition to the new set of functions for data loading. See the [Migration Guide](https://boehringer-ingelheim.github.io/dv.loader/articles/migration-guide.html) vignette for more details.
 
-```r
-# getting data from a network file storage folder
-dv.loader::load_data(sub_dir = "subdir1/subdir2", file_names = c("adsl", "adae"))
-```
+## Main Functions
+
+The package includes a collection of functions designed to handle various file formats. 
+
+- `load_rds()`: Imports RDS files (extension: `.rds`)
+- `load_sas()`: Imports SAS files (extension: `.sas7bdat`)
+- `load_xpt()`: Imports XPT files (extension: `.xpt`)
+
+These functions provide error handling, metadata extraction, and return a consistent output format of named lists containing data frames and associated metadata, streamlining the process of importing multiple data files in R.
+
+## Working Example
+
+To illustrate the usage of {dv.loader}, let's explore a hands-on example using the `load_sas()` function to import SAS data. This example serves as a template for working with other file formats, as `load_rds()` and `load_xpt()` functions operate in a similar manner.
 
 ```r
-# getting data locally (e.g., if you have file `./data/adsl.RDS`)
-dv.loader::load_data(sub_dir = "data", file_names = c("adsl"), use_wd = TRUE)
+# Identify the path to the directory containing the data files
+data_dir <- system.file("extdata", "pharmaverseadam", package = "dv.loader")
+
+# Provide the vector of file names to be loaded
+file_names <- paste0(c("adsl", "adae"), ".sas7bdat")
+
+# Load SAS data files from the specified directory
+dv.loader::load_sas(files = file.path(data_dir, file_names))
 ```
diff --git a/_pkgdown.yml b/_pkgdown.yml
index 3cc3a6f..8de0756 100644
--- a/_pkgdown.yml
+++ b/_pkgdown.yml
@@ -9,8 +9,9 @@ navbar:
     qc:
       text: Quality Control
       href: articles/qc.html
+
 home:
-  title: dv.loader
+  title: Data Loader for DaVinci Modular Applications
   links:
   - text: Browse source code
     href: https://github.com/Boehringer-Ingelheim/dv.loader
diff --git a/inst/extdata/data.R b/inst/extdata/data.R
new file mode 100644
index 0000000..2dd1a3d
--- /dev/null
+++ b/inst/extdata/data.R
@@ -0,0 +1,36 @@
+# Save data to inst/extdata
+data_dir <- "inst/extdata"
+
+# Create directory for pharmaverseadam data
+if (!dir.exists(file.path(data_dir, "pharmaverseadam"))) {
+  dir.create(file.path(data_dir, "pharmaverseadam"), recursive = TRUE)
+}
+
+# Save adsl data
+haven::write_sas(
+  data = pharmaverseadam::adsl,
+  path = file.path(data_dir, "pharmaverseadam", "adsl.sas7bdat")
+)
+
+# Save adae data
+haven::write_sas(
+  data = pharmaverseadam::adae,
+  path = file.path(data_dir, "pharmaverseadam", "adae.sas7bdat")
+)
+
+# Create directory for pharmaversesdtm data
+if (!dir.exists(file.path(data_dir, "pharmaversesdtm"))) {
+  dir.create(file.path(data_dir, "pharmaversesdtm"), recursive = TRUE)
+}
+
+# Save dm data
+haven::write_sas(
+  data = pharmaversesdtm::dm,
+  path = file.path(data_dir, "pharmaversesdtm", "dm.sas7bdat")
+)
+
+# Save ae data
+haven::write_sas(
+  data = pharmaversesdtm::ae,
+  path = file.path(data_dir, "pharmaversesdtm", "ae.sas7bdat")
+)
diff --git a/inst/extdata/pharmaverseadam/adae.sas7bdat b/inst/extdata/pharmaverseadam/adae.sas7bdat
new file mode 100644
index 0000000..1a5c7e9
Binary files /dev/null and b/inst/extdata/pharmaverseadam/adae.sas7bdat differ
diff --git a/inst/extdata/pharmaverseadam/adsl.sas7bdat b/inst/extdata/pharmaverseadam/adsl.sas7bdat
new file mode 100644
index 0000000..f0e27d6
Binary files /dev/null and b/inst/extdata/pharmaverseadam/adsl.sas7bdat differ
diff --git a/inst/extdata/pharmaversesdtm/ae.sas7bdat b/inst/extdata/pharmaversesdtm/ae.sas7bdat
new file mode 100644
index 0000000..7e30215
Binary files /dev/null and b/inst/extdata/pharmaversesdtm/ae.sas7bdat differ
diff --git a/inst/extdata/pharmaversesdtm/dm.sas7bdat b/inst/extdata/pharmaversesdtm/dm.sas7bdat
new file mode 100644
index 0000000..2758b06
Binary files /dev/null and b/inst/extdata/pharmaversesdtm/dm.sas7bdat differ
diff --git a/man/check_file_ext.Rd b/man/check_file_ext.Rd
new file mode 100644
index 0000000..9528434
--- /dev/null
+++ b/man/check_file_ext.Rd
@@ -0,0 +1,19 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/utils.R
+\name{check_file_ext}
+\alias{check_file_ext}
+\title{Check if a file has a specific extension (case-insensitive)}
+\usage{
+check_file_ext(file, extension)
+}
+\arguments{
+\item{file}{A character string specifying the path to the file.}
+
+\item{extension}{A character string specifying the expected file extension (without the dot).}
+}
+\value{
+A logical value: TRUE if the file has the specified extension, FALSE otherwise.
+}
+\description{
+This function checks if a given file has a specific extension, ignoring case.
+}
diff --git a/man/create_data_list.Rd b/man/create_data_list.Rd
index 2368307..b945601 100644
--- a/man/create_data_list.Rd
+++ b/man/create_data_list.Rd
@@ -1,5 +1,5 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/utils.R
+% Please edit documentation in R/load_data.R
 \name{create_data_list}
 \alias{create_data_list}
 \title{For each file name provided, reads in the first matching file and its meta data/attributes.
diff --git a/man/file_info.Rd b/man/file_info.Rd
new file mode 100644
index 0000000..33c113c
--- /dev/null
+++ b/man/file_info.Rd
@@ -0,0 +1,17 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/utils.R
+\name{file_info}
+\alias{file_info}
+\title{Extract file information based on file.info()}
+\usage{
+file_info(file)
+}
+\arguments{
+\item{file}{A character string specifying the path to the file.}
+}
+\value{
+A list containing file information from file.info(file, extra_cols = FALSE) and the path and file name.
+}
+\description{
+This function extracts file information from a given file.
+}
diff --git a/man/get_cre_path.Rd b/man/get_cre_path.Rd
index 86b2b78..d68a42b 100644
--- a/man/get_cre_path.Rd
+++ b/man/get_cre_path.Rd
@@ -1,5 +1,5 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/dvloader.R
+% Please edit documentation in R/load_data.R
 \name{get_cre_path}
 \alias{get_cre_path}
 \title{gets the NFS base path from an env var
diff --git a/man/get_nfs_path.Rd b/man/get_nfs_path.Rd
index 5cbad09..07273b5 100644
--- a/man/get_nfs_path.Rd
+++ b/man/get_nfs_path.Rd
@@ -1,5 +1,5 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/dvloader.R
+% Please edit documentation in R/load_data.R
 \name{get_nfs_path}
 \alias{get_nfs_path}
 \title{gets the NFS base path from an env var
diff --git a/man/load_data.Rd b/man/load_data.Rd
index 5367158..8d44207 100644
--- a/man/load_data.Rd
+++ b/man/load_data.Rd
@@ -1,5 +1,5 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/dvloader.R
+% Please edit documentation in R/load_data.R
 \name{load_data}
 \alias{load_data}
 \title{Loads data into memory based on study directory and one or more file_names.}
@@ -7,7 +7,7 @@
 load_data(sub_dir = NULL, file_names, use_wd = FALSE, prefer_sas = FALSE)
 }
 \arguments{
-\item{sub_dir}{A relative directory/folder that will be appended to a base path defined by `Sys.getenv("RXD_DATA")`. 
+\item{sub_dir}{A relative directory/folder that will be appended to a base path defined by `Sys.getenv("RXD_DATA")`.
 If the argument is left as NULL, the function will load data from the working directory `getwd()`.}
 
 \item{file_names}{Study file or file_names name(s) - can be a vector of strings.
diff --git a/man/load_rds.Rd b/man/load_rds.Rd
new file mode 100644
index 0000000..c82a15b
--- /dev/null
+++ b/man/load_rds.Rd
@@ -0,0 +1,33 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/load_rds.R
+\name{load_rds}
+\alias{load_rds}
+\title{Load RDS files}
+\usage{
+load_rds(files)
+}
+\arguments{
+\item{files}{A character vector of file paths to RDS files.}
+}
+\value{
+A list of data frames, each containing the data from an RDS file.
+}
+\description{
+This function loads RDS files via readRDS() and returns a list of data frames.
+}
+\examples{
+# Create temporary directory and files
+temp_dir <- tempdir()
+adsl_rds_file <- file.path(temp_dir, "adsl.rds")
+adae_rds_file <- file.path(temp_dir, "adae.rds")
+
+# Write example data to RDS files
+saveRDS(pharmaverseadam::adsl, adsl_rds_file)
+saveRDS(pharmaverseadam::adae, adae_rds_file)
+
+# Load RDS files
+rds_data_list <- load_rds(c(adsl_rds_file, adae_rds_file))
+
+# Clean up
+unlink(c(adsl_rds_file, adae_rds_file))
+}
diff --git a/man/load_sas.Rd b/man/load_sas.Rd
new file mode 100644
index 0000000..e434167
--- /dev/null
+++ b/man/load_sas.Rd
@@ -0,0 +1,33 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/load_sas.R
+\name{load_sas}
+\alias{load_sas}
+\title{Load SAS files}
+\usage{
+load_sas(files)
+}
+\arguments{
+\item{files}{A character vector of file paths to SAS files.}
+}
+\value{
+A list of data frames, each containing the data from a SAS file.
+}
+\description{
+This function loads SAS files via haven::read_sas() and returns a list of data frames.
+}
+\examples{
+# Create temporary directory and files
+temp_dir <- tempdir()
+adsl_sas_file <- file.path(temp_dir, "adsl.sas7bdat")
+adae_sas_file <- file.path(temp_dir, "adae.sas7bdat")
+
+# Write example data to SAS files
+haven::write_sas(pharmaverseadam::adsl, adsl_sas_file)
+haven::write_sas(pharmaverseadam::adae, adae_sas_file)
+
+# Load SAS files
+sas_data_list <- load_sas(c(adsl_sas_file, adae_sas_file))
+
+# Clean up
+unlink(c(adsl_sas_file, adae_sas_file))
+}
diff --git a/man/load_xpt.Rd b/man/load_xpt.Rd
new file mode 100644
index 0000000..80a6a01
--- /dev/null
+++ b/man/load_xpt.Rd
@@ -0,0 +1,33 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/load_xpt.R
+\name{load_xpt}
+\alias{load_xpt}
+\title{Load XPT files}
+\usage{
+load_xpt(files)
+}
+\arguments{
+\item{files}{A character vector of file paths to XPT files.}
+}
+\value{
+A list of data frames, each containing the data from an XPT file.
+}
+\description{
+This function loads XPT files via haven::read_xpt() and returns a list of data frames.
+}
+\examples{
+# Create temporary directory and files
+temp_dir <- tempdir()
+adsl_xpt_file <- file.path(temp_dir, "adsl.xpt")
+adae_xpt_file <- file.path(temp_dir, "adae.xpt")
+
+# Write example data to XPT files
+haven::write_xpt(pharmaverseadam::adsl, adsl_xpt_file)
+haven::write_xpt(pharmaverseadam::adae, adae_xpt_file)
+
+# Load XPT files
+xpt_data_list <- load_xpt(c(adsl_xpt_file, adae_xpt_file))
+
+# Clean up
+unlink(c(adsl_xpt_file, adae_xpt_file))  
+}
diff --git a/man/read_file.Rd b/man/read_file.Rd
index e46767b..c07c14f 100644
--- a/man/read_file.Rd
+++ b/man/read_file.Rd
@@ -1,5 +1,5 @@
 % Generated by roxygen2: do not edit by hand
-% Please edit documentation in R/utils.R
+% Please edit documentation in R/load_data.R
 \name{read_file}
 \alias{read_file}
 \title{Reads RDS/SAS file and metadatas from first 6 items from file.info() its file path}
diff --git a/tests/testthat/inst/extdata/bad_file_type.myrds b/tests/testthat/inst/extdata/bad_file_type.myrds
deleted file mode 100644
index 2ca4327..0000000
Binary files a/tests/testthat/inst/extdata/bad_file_type.myrds and /dev/null differ
diff --git a/tests/testthat/inst/extdata/bad_file_type.txt b/tests/testthat/inst/extdata/bad_file_type.txt
deleted file mode 100644
index e69de29..0000000
diff --git a/tests/testthat/inst/extdata/dummyads1.RDS b/tests/testthat/inst/extdata/dummyads1.RDS
deleted file mode 100644
index 06add3b..0000000
Binary files a/tests/testthat/inst/extdata/dummyads1.RDS and /dev/null differ
diff --git a/tests/testthat/inst/extdata/dummyads1.sas7bdat b/tests/testthat/inst/extdata/dummyads1.sas7bdat
deleted file mode 100644
index bc7cb8a..0000000
Binary files a/tests/testthat/inst/extdata/dummyads1.sas7bdat and /dev/null differ
diff --git a/tests/testthat/inst/extdata/dummyads2.RDS b/tests/testthat/inst/extdata/dummyads2.RDS
deleted file mode 100644
index 2ca4327..0000000
Binary files a/tests/testthat/inst/extdata/dummyads2.RDS and /dev/null differ
diff --git a/tests/testthat/inst/extdata/dummyads2.sas7bdat b/tests/testthat/inst/extdata/dummyads2.sas7bdat
deleted file mode 100644
index 6eeec6d..0000000
Binary files a/tests/testthat/inst/extdata/dummyads2.sas7bdat and /dev/null differ
diff --git a/tests/testthat/inst/extdata/just_rds/dummyads1.RDS b/tests/testthat/inst/extdata/just_rds/dummyads1.RDS
deleted file mode 100644
index 06add3b..0000000
Binary files a/tests/testthat/inst/extdata/just_rds/dummyads1.RDS and /dev/null differ
diff --git a/tests/testthat/inst/extdata/just_rds/dummyads2.RDS b/tests/testthat/inst/extdata/just_rds/dummyads2.RDS
deleted file mode 100644
index 2ca4327..0000000
Binary files a/tests/testthat/inst/extdata/just_rds/dummyads2.RDS and /dev/null differ
diff --git a/tests/testthat/inst/extdata/just_sas/dummyads1.sas7bdat b/tests/testthat/inst/extdata/just_sas/dummyads1.sas7bdat
deleted file mode 100644
index bc7cb8a..0000000
Binary files a/tests/testthat/inst/extdata/just_sas/dummyads1.sas7bdat and /dev/null differ
diff --git a/tests/testthat/inst/extdata/just_sas/dummyads2.sas7bdat b/tests/testthat/inst/extdata/just_sas/dummyads2.sas7bdat
deleted file mode 100644
index 6eeec6d..0000000
Binary files a/tests/testthat/inst/extdata/just_sas/dummyads2.sas7bdat and /dev/null differ
diff --git a/tests/testthat/setup.R b/tests/testthat/setup.R
index 1dab7a6..ac6ce9e 100644
--- a/tests/testthat/setup.R
+++ b/tests/testthat/setup.R
@@ -1,25 +1,66 @@
 # validation (S)
 vdoc <- local({
-  #                      ##########
-  # package_name is used # INSIDE # the sourced file below
-  #                      ##########
-  package_name <- read.dcf("../../DESCRIPTION")[, "Package"]
+  package_name <- "dv.loader" # package_name is used *INSIDE* the sourced file below
   utils_file_path <- system.file("validation", "utils-validation.R", package = package_name, mustWork = TRUE)
-  source(utils_file_path, local = TRUE)[["value"]]
+  source(file = utils_file_path, local = TRUE)[["value"]]
 })
+
 specs <- vdoc[["specs"]]
-#  validation (F)
+# validation (F)
+
+# Create a copy of the iris data
+iris_data <- iris
+
+# Change . to _ in column names
+names(iris_data) <- gsub("\\.", "_", names(iris_data))
+
+# Create a temporary directory
+temp_dir <- tempdir()
 
-Sys.setenv("RXD_DATA" = find.package(package = "dv.loader"))
-local_test_path <- "inst/extdata"
+# Path to the data files
+iris_file <- file.path(temp_dir, "iris")
+iris_rds_file <- file.path(temp_dir, "iris.rds")
+iris_sas_file <- file.path(temp_dir, "iris.sas7bdat")
+iris_xpt_file <- file.path(temp_dir, "iris.xpt")
+iris_txt_file <- file.path(temp_dir, "iris.txt")
 
-test_file_path <- "test/"
-cre_test_files <- c("adsl.sas7bdat", "adae.sas7bdat")
-cre_file_names <- c("adsl", "adae")
-local_test_files <- c("dummyads1.sas7bdat", "dummyads2.sas7bdat")
-local_file_names <- c("dummyads1", "dummyads2")
+# Save data to file with no extension
+saveRDS(iris_data, iris_file)
 
-expected_meta_cols <- c(
-  "size", "isdir", "mode", "mtime",
-  "ctime", "atime", "path", "file_name"
+# Save iris data to RDS file
+saveRDS(iris_data, iris_rds_file)
+
+# Save iris data to SAS file
+lifecycle::expect_deprecated(
+  haven::write_sas(iris_data, iris_sas_file)
 )
+
+# Save iris data to XPT file
+haven::write_xpt(iris_data, iris_xpt_file)
+
+# Save iris data to TXT file
+write.table(iris_data, file = iris_txt_file, row.names = FALSE)
+
+# Set the RXD_DATA environment variable
+Sys.setenv(RXD_DATA = temp_dir)
+
+# Load RDS data via load_data()
+lifecycle::expect_deprecated(
+  iris_data_rds <- dv.loader::load_data(
+    sub_dir = ".", 
+    file_names = "iris.rds"
+  )
+)
+
+# Load SAS data via load_data()
+lifecycle::expect_deprecated(
+  iris_data_sas <- dv.loader::load_data(
+    sub_dir = ".", 
+    file_names = "iris.sas7bdat"
+  )
+)
+
+# Load the data from the files
+iris_rds <- dv.loader::load_rds(files = iris_rds_file)
+iris_sas <- dv.loader::load_sas(files = iris_sas_file)
+iris_xpt <- dv.loader::load_xpt(files = iris_xpt_file)
diff --git a/tests/testthat/test-data_integrity.R b/tests/testthat/test-data_integrity.R
new file mode 100644
index 0000000..a8cc040
--- /dev/null
+++ b/tests/testthat/test-data_integrity.R
@@ -0,0 +1,42 @@
+test_that(
+  desc = vdoc[["add_spec"]](
+    desc = "Ensures that the data integrity is maintained across different file types and loading methods, comparing the loaded data against a known reference dataset.",
+    spec = specs$data_integrity
+  ), 
+  code = { 
+    # load_data(): check that the RDS file is loaded correctly
+    expect_equal(
+      object = iris_data_rds[["iris.rds"]],
+      expected = iris_data,
+      ignore_attr = TRUE
+    )
+    
+    # load_data(): check that the SAS file is loaded correctly
+    expect_equal(
+      object = iris_data_sas[["iris.sas7bdat"]],
+      expected = iris_data,
+      ignore_attr = TRUE
+    )
+
+    # load_rds(): check that the RDS file is loaded correctly
+    expect_equal(
+      object = iris_rds[["iris.rds"]], 
+      expected = iris_data,
+      ignore_attr = TRUE
+    )
+    
+    # load_sas(): check that the SAS file is loaded correctly
+    expect_equal(
+      object = iris_sas[["iris.sas7bdat"]], 
+      expected = iris_data,
+      ignore_attr = TRUE
+    )
+    
+    # load_xpt(): check that the XPT file is loaded correctly
+    expect_equal(
+      object = iris_xpt[["iris.xpt"]], 
+      expected = iris_data,
+      ignore_attr = TRUE
+    )
+  }
+)
diff --git a/tests/testthat/test-default_dir.R b/tests/testthat/test-default_dir.R
new file mode 100644
index 0000000..b9336fe
--- /dev/null
+++ b/tests/testthat/test-default_dir.R
@@ -0,0 +1,43 @@
+test_that(  
+  desc = vdoc[["add_spec"]](
+    desc = "Verifies that load_data() can correctly locate and load data files using relative paths from the current working directory.",
+    spec = specs$default_dir
+  ), 
+  code = {
+    # Save the current working directory
+    old_wd <- getwd()
+    
+    # Change the working directory to the temporary directory
+    setwd(temp_dir)
+    
+    lifecycle::expect_deprecated(
+      # load_data(): load the RDS file with use_wd = TRUE
+      data1 <- dv.loader::load_data(
+        sub_dir = ".",
+        file_names = "iris.rds",
+        use_wd = TRUE
+      )    
+    )
+
+    lifecycle::expect_deprecated(
+      # load_data(): load the SAS file with use_wd = TRUE
+      data2 <- dv.loader::load_data(
+        sub_dir = ".",
+        file_names = "iris.sas7bdat",
+        use_wd = TRUE
+      )      
+    )
+
+    # Expect that the RDS file is loaded
+    expect_named(data1, "iris.rds")
+
+    # Expect that the SAS file is loaded
+    expect_named(data2, "iris.sas7bdat")
+
+    # Expect that the two data sets are the same
+    expect_equal(data1, data2, ignore_attr = TRUE)
+
+    # Set the working directory back to the original directory
+    setwd(old_wd)
+  }
+)
diff --git a/tests/testthat/test-file_extensions.R b/tests/testthat/test-file_extensions.R
new file mode 100644
index 0000000..dd9a6dd
--- /dev/null
+++ b/tests/testthat/test-file_extensions.R
@@ -0,0 +1,28 @@
+test_that(
+  desc = vdoc[["add_spec"]](
+    desc = "appropriate error messages are thrown when attempting to load or read files without valid extensions",
+    spec = specs$file_extensions
+  ), 
+  code = {
+    # load_data(): load data with no file extension
+    lifecycle::expect_deprecated(
+      dv.loader::load_data(sub_dir = ".", file_names = "iris")
+    ) |>
+      expect_error("file must either be RDS or SAS7BDAT")
+    
+    # Expected error message
+    error_msg <- "Assertion on 'file_ext != \"\"' failed: Must be TRUE."
+
+    # load_rds(): expect an error when the file extension is empty
+    dv.loader::load_rds(files = iris_file) |> 
+      expect_error(error_msg) 
+
+    # load_sas(): expect an error when the file extension is empty
+    dv.loader::load_sas(files = iris_file) |> 
+      expect_error(error_msg)
+
+    # load_xpt(): expect an error when the file extension is empty
+    dv.loader::load_xpt(files = iris_file) |> 
+      expect_error(error_msg)
+  }
+)
diff --git a/tests/testthat/test-file_names.R b/tests/testthat/test-file_names.R
new file mode 100644
index 0000000..4212ae9
--- /dev/null
+++ b/tests/testthat/test-file_names.R
@@ -0,0 +1,25 @@
+test_that(
+  desc = vdoc[["add_spec"]](
+    desc = "appropriate error messages are thrown when the required 'file_names' argument is not provided",
+    spec = specs$file_names
+  ), 
+  code = {
+    lifecycle::expect_deprecated(
+     # load_data(): expect an error when the file_names argument is missing
+      load_data(sub_dir = ".")
+    ) |>
+      expect_error('argument "file_names" is missing, with no default')
+    
+    # Expected error message
+    error_msg <- 'argument "files" is missing, with no default'
+
+    # load_rds(): expect an error when the files argument is missing
+    expect_error(dv.loader::load_rds(), error_msg)
+    
+    # load_sas(): expect an error when the files argument is missing
+    expect_error(dv.loader::load_sas(), error_msg)
+    
+    # load_xpt(): expect an error when the files argument is missing
+    expect_error(dv.loader::load_xpt(), error_msg)
+  }
+)
diff --git a/tests/testthat/test-file_type.R b/tests/testthat/test-file_type.R
new file mode 100644
index 0000000..59bec5b
--- /dev/null
+++ b/tests/testthat/test-file_type.R
@@ -0,0 +1,25 @@
+test_that(
+  desc = vdoc[["add_spec"]](
+    desc = "appropriate error messages are thrown when attempting to load or read file with types that are not supported.",
+    spec = specs$file_type
+  ), 
+  code = {   
+    # load_data(): expect an error when the file type is not supported
+    lifecycle::expect_deprecated(
+      dv.loader::load_data(sub_dir = ".", file_names = "iris.txt")
+    ) |>
+      expect_error("file must either be RDS or SAS7BDAT")
+    
+    # Expected error message
+    error_msg <- "Must be element of set \\{'rds','sas7bdat','xpt'\\}, but is 'txt'."
+    
+    # load_rds(): expect an error when the file extension is not supported
+    expect_error(dv.loader::load_rds(files = iris_txt_file), error_msg)
+    
+    # load_sas(): expect an error when the file extension is not supported
+    expect_error(dv.loader::load_sas(files = iris_txt_file), error_msg)
+    
+    # load_xpt(): expect an error when the file extension is not supported
+    expect_error(dv.loader::load_xpt(files = iris_txt_file), error_msg)
+  }
+)
diff --git a/tests/testthat/test-meta_data.R b/tests/testthat/test-meta_data.R
new file mode 100644
index 0000000..227e5db
--- /dev/null
+++ b/tests/testthat/test-meta_data.R
@@ -0,0 +1,42 @@
+test_that(
+  desc = vdoc[["add_spec"]](
+    desc = "load_data(), load_rds(), load_sas(), and load_xpt() functions correctly extract and attach metadata of the file to the loaded data",
+    spec = specs$meta_data
+  ),
+  code = {
+    # Get the file info for the iris files
+    rds_file_info <- file.info(iris_rds_file, extra_cols = FALSE)
+    sas_file_info <- file.info(iris_sas_file, extra_cols = FALSE)
+    xpt_file_info <- file.info(iris_xpt_file, extra_cols = FALSE)
+    
+    # load_data(): check metadata for RDS file
+    expect_equal(
+      as.list(attr(iris_data_rds[["iris.rds"]], "meta")[names(rds_file_info)]), 
+      as.list(rds_file_info)
+    )
+    
+    # load_data(): check metadata for SAS file
+    expect_equal(
+      as.list(attr(iris_data_sas[["iris.sas7bdat"]], "meta")[names(sas_file_info)]), 
+      as.list(sas_file_info)
+    )
+    
+    # load_rds(): check metadata for RDS file
+    expect_equal(
+      as.list(attr(iris_rds[["iris.rds"]], "meta")[names(rds_file_info)]), 
+      as.list(rds_file_info)
+    )
+    
+    # load_sas(): check metadata for SAS file
+    expect_equal(
+      as.list(attr(iris_sas[["iris.sas7bdat"]], "meta")[names(sas_file_info)]), 
+      as.list(sas_file_info)
+    )
+    
+    # load_xpt(): check metadata for XPT file
+    expect_equal(
+      as.list(attr(iris_xpt[["iris.xpt"]], "meta")[names(xpt_file_info)]), 
+      as.list(xpt_file_info)
+    )
+  }
+)
diff --git a/tests/testthat/test-prefer_sas.R b/tests/testthat/test-prefer_sas.R
new file mode 100644
index 0000000..837ba34
--- /dev/null
+++ b/tests/testthat/test-prefer_sas.R
@@ -0,0 +1,37 @@
+test_that(
+  desc = vdoc[["add_spec"]](
+    desc = "load_data() loads the RDS file if prefer_sas is FALSE, and it loads the SAS file if prefer_sas is TRUE.",
+    spec = specs$prefer_sas
+  ), 
+  code = {
+    # load_data(): load the RDS file with prefer_sas = FALSE
+    lifecycle::expect_deprecated(
+      data_rds <- dv.loader::load_data(
+        sub_dir = ".",
+        file_names = "iris.rds",
+        prefer_sas = FALSE 
+      )
+    )
+    
+    # load_data(): load the SAS file with prefer_sas = TRUE
+    lifecycle::expect_deprecated(
+      data_sas <- load_data(
+        sub_dir = ".", 
+        file_names = "iris.sas7bdat",
+        prefer_sas = TRUE
+      )
+    )
+    
+    # Get metadata for RDS file
+    meta_rds <- attr(data_rds[["iris.rds"]], "meta")
+    
+    # Get metadata for SAS file
+    meta_sas <- attr(data_sas[["iris.sas7bdat"]], "meta")
+    
+    # Check if the correct RDS file is loaded
+    expect_equal(basename(meta_rds[["path"]]), "iris.rds")  
+    
+    # Check if the correct file is loaded
+    expect_equal(basename(meta_sas[["path"]]), "iris.sas7bdat")
+  }
+)
diff --git a/tests/testthat/tests.R b/tests/testthat/tests.R
deleted file mode 100644
index d5e5747..0000000
--- a/tests/testthat/tests.R
+++ /dev/null
@@ -1,207 +0,0 @@
-test_that(
-  "defaults to using the working directory when sub_dir arg is NULL" %>%
-    vdoc[["add_spec"]](specs$default_dir),
-  {
-    expect_error(
-      load_data(file_names = local_file_names)
-    )
-  }
-)
-
-test_that(
-  "throws an error if you don't provide 'file_names'" %>%
-    vdoc[["add_spec"]](specs$file_names),
-  {
-    expect_error(
-      load_data(file_names = NULL)
-    )
-  }
-)
-
-test_that(
-  "throws an error if you provide a file type which is not supported" %>%
-    vdoc[["add_spec"]](specs$file_type),
-  {
-    expect_error(
-      load_data(
-        sub_dir = local_test_path,
-        file_names = "bad_file_type"
-      )
-    )
-  }
-)
-
-test_that(
-  "does not throw an error if provided valid extensions" %>%
-    vdoc[["add_spec"]](specs$file_extensions),
-  {
-    expect_error(
-      load_data(
-        sub_dir = local_test_path,
-        file_names = "dummyads1.RDS",
-        use_wd = TRUE
-      ),
-      NA
-    )
-  }
-)
-
-
-test_that(
-  "can mix file_names with valid extensions" %>%
-    vdoc[["add_spec"]](specs$file_extensions),
-  {
-    actual <- load_data(
-      sub_dir = local_test_path,
-      file_names = c("dummyads1.RDS", "dummyads1.sas7bdat"),
-      use_wd = TRUE
-    )
-    actual <- c(
-      tools::file_ext(attributes(actual[[1]])$meta$path),
-      tools::file_ext(attributes(actual[[2]])$meta$path)
-    )
-    expected <- c("RDS", "sas7bdat")
-    expect_equal(actual, expected)
-  }
-)
-
-test_that(
-  "can mix file_names with and without valid extensions" %>%
-    vdoc[["add_spec"]](specs$file_extensions),
-  {
-    expect_error(
-      load_data(
-        sub_dir = local_test_path,
-        file_names = c("dummyads1", "dummyads2.RDS"),
-        use_wd = TRUE
-      ),
-      NA
-    )
-  }
-)
-
-test_that(
-  "does not throw an error if you provide valid extensions" %>%
-    vdoc[["add_spec"]](specs$file_extensions),
-  {
-    expect_error(
-      load_data(
-        sub_dir = local_test_path,
-        file_names = c("bad_file_type.txt"),
-        use_wd = TRUE
-      )
-    )
-    expect_error(
-      load_data(
-        sub_dir = local_test_path,
-        file_names = c("bad_file_type.myrds"),
-        use_wd = TRUE
-      )
-    )
-  }
-)
-
-test_that(
-  "maintains integrity of data from producing system to consuming system" %>%
-    vdoc[["add_spec"]](specs$data_integrity),
-  {
-    actual <- load_data(
-      sub_dir = local_test_path,
-      file_names = local_file_names[2],
-      use_wd = TRUE,
-      prefer_sas = TRUE
-    )
-
-    actual <- actual[[1]]
-
-    attr(actual, "meta") <- NULL
-    attr(actual, "label") <- "dummyads2"
-
-    expected <- haven::read_sas(file.path(local_test_path, local_test_files[2]))
-    attr(expected, "label") <- "dummyads2"
-
-    expect_equal(
-      actual,
-      expected
-    )
-  }
-)
-
-test_that(
-  "has correct metadata" %>%
-    vdoc[["add_spec"]](specs$meta_data),
-  {
-    actual <- load_data(
-      sub_dir = local_test_path,
-      file_names = local_file_names[2],
-      use_wd = TRUE
-    )
-    actual_meta <- attr(actual[[1]], "meta")
-    expect_equal(
-      c(
-        "size", "isdir", "mode",
-        "mtime", "ctime", "atime",
-        "path", "file_name"
-      ),
-      names(actual_meta)
-    )
-  }
-)
-
-test_that(
-  "loads an RDS file when prefer_sas is FALSE (default) and both SAS and RDS files exist" %>%
-    vdoc[["add_spec"]](specs$prefer_sas),
-  {
-    actual <- load_data(
-      sub_dir = local_test_path,
-      file_names = local_file_names[2],
-      use_wd = TRUE
-    )
-    actual <- attr(actual[[1]], "meta")[["path"]]
-    expect_equal(grepl(".RDS$", actual, ignore.case = FALSE), TRUE)
-  }
-)
-
-test_that(
-  "loads a SAS file when prefer_sas is FALSE (default) and an RDS file doesn't exist" %>%
-    vdoc[["add_spec"]](specs$prefer_sas),
-  {
-    actual <- load_data(
-      sub_dir = file.path(local_test_path, "just_sas"),
-      file_names = local_file_names[2],
-      use_wd = TRUE
-    )
-    actual <- attr(actual[[1]], "meta")[["path"]]
-    expect_equal(grepl(".sas7bdat$", actual, ignore.case = TRUE), TRUE)
-  }
-)
-
-test_that(
-  "loads a SAS file when prefer_sas is TRUE and both SAS and RDS files exist" %>%
-    vdoc[["add_spec"]](specs$prefer_sas),
-  {
-    actual <- load_data(
-      sub_dir = local_test_path,
-      file_names = local_file_names[2],
-      use_wd = TRUE,
-      prefer_sas = TRUE
-    )
-    actual <- attr(actual[[1]], "meta")[["path"]]
-    expect_equal(grepl(".sas7bdat$", actual), TRUE)
-  }
-)
-
-test_that(
-  "loads an RDS file when prefer_sas is TRUE and a SAS file doesn't exist" %>%
-    vdoc[["add_spec"]](specs$prefer_sas),
-  {
-    actual <- load_data(
-      sub_dir = file.path(local_test_path, "just_rds"),
-      file_names = local_file_names[2],
-      use_wd = TRUE,
-      prefer_sas = TRUE
-    )
-    actual <- attr(actual[[1]], "meta")[["path"]]
-    expect_equal(grepl(".RDS$", actual), TRUE)
-  }
-)
diff --git a/vignettes/.gitignore b/vignettes/.gitignore
new file mode 100644
index 0000000..097b241
--- /dev/null
+++ b/vignettes/.gitignore
@@ -0,0 +1,2 @@
+*.html
+*.R
diff --git a/vignettes/integration-guide.Rmd b/vignettes/integration-guide.Rmd
new file mode 100644
index 0000000..f6393de
--- /dev/null
+++ b/vignettes/integration-guide.Rmd
@@ -0,0 +1,74 @@
+---
+title: "Integration Guide"
+output: rmarkdown::html_vignette
+vignette: >
+  %\VignetteIndexEntry{Integration Guide}
+  %\VignetteEngine{knitr::rmarkdown}
+  %\VignetteEncoding{UTF-8}
+---
+
+```{r, include = FALSE}
+knitr::opts_chunk$set(
+  collapse = TRUE,
+  comment = "#>"
+)
+```
+
+This vignette showcases the integration of the {dv.loader} package with other packages from the DaVinci framework. It guides you through the process of combining {dv.loader} with {dv.manager} and {dv.listings} to create a modular Shiny application.
+
+```{r, eval=FALSE}
+# Install the {remotes} package if you haven't already
+if (!require("remotes")) install.packages("remotes")
+
+# Define the packages to install
+pkgs <- c("dv.loader", "dv.manager", "dv.listings")
+
+# Install the packages from GitHub
+remotes::install_github(repo = paste0("Boehringer-Ingelheim/", pkgs))
+```
+
+## Step 1: Load data files
+
+Use the `dv.loader::load_sas()` function to import two example SAS data files included in the `dv.loader` package.
+
+```{r, eval=FALSE}
+# Define the directory containing the data files
+data_dir <- system.file("extdata", "pharmaverseadam", package = "dv.loader")
+
+# Define the file names
+file_names <- paste0(c("adsl", "adae"), ".sas7bdat")
+
+# Import the data files
+data_list <- dv.loader::load_sas(files = file.path(data_dir, file_names))
+
+# Remove file extensions from the dataset names
+names(data_list) <- tools::file_path_sans_ext(names(data_list))
+```
+
+## Step 2: Create a module list
+
+Utilize `dv.listings::mod_listings()` to generate a module that presents tabular views of the two datasets imported in the preceding step.
+
+```{r, eval=FALSE}
+# Include a module containing two data listings
+module_list <- list(
+  "Data Listings" = dv.listings::mod_listings(
+    module_id = "data_listings",
+    dataset_names = c("adsl", "adae")
+  )
+)
+```
+
+## Step 3: Run the DaVinci application
+
+Execute the `dv.manager::run_app()` function to initiate the DaVinci application, incorporating the data and module lists prepared in the preceding steps.
+
+```{r, eval=FALSE}
+# Run the DaVinci application with data and module lists defined earlier
+dv.manager::run_app(
+  data = list("pharmaverseadam" = data_list), 
+  module_list = module_list,
+  filter_data = "adsl",
+  title = "DaVinci Application"
+)
+```
diff --git a/vignettes/loading-data-into-memory.Rmd b/vignettes/loading-data-into-memory.Rmd
deleted file mode 100644
index 577da15..0000000
--- a/vignettes/loading-data-into-memory.Rmd
+++ /dev/null
@@ -1,45 +0,0 @@
----
-title: "Loading Data into Memory"
-output: rmarkdown::html_vignette
-vignette: >
-  %\VignetteIndexEntry{Loading Data into Memory}
-  %\VignetteEngine{knitr::rmarkdown}
-  %\VignetteEncoding{UTF-8}
----
-
-```{r, include = FALSE}
-knitr::opts_chunk$set(
-  collapse = TRUE,
-  comment = "#>"
-)
-```
-
-```{r setup}
-library(dv.loader)
-```
-
-Note: `use_wd = TRUE` can be used to source from local folder. Just set your working directory before using with `setwd()`, or use an explicit path in `sub_dir`.
-
-## Usage: `load_data()`
-
-```{r}
-test_data_path <- "../tests/testthat/inst/extdata"
-data_list <- load_data(
-  sub_dir = test_data_path,
-  file_names = "dummyads2",
-  use_wd = TRUE
-)
-
-
-class(data_list)
-
-class(data_list[["dummyads2"]])
-
-head(data_list[["dummyads2"]])
-```
-
-Get the dataframe's metadata through its attributes:
-
-```{r}
-attr(data_list[["dummyads2"]], "meta")
-```
diff --git a/vignettes/migration-guide.Rmd b/vignettes/migration-guide.Rmd
new file mode 100644
index 0000000..5cbe1e1
--- /dev/null
+++ b/vignettes/migration-guide.Rmd
@@ -0,0 +1,118 @@
+---
+title: "Migration Guide"
+output: rmarkdown::html_vignette
+vignette: >
+  %\VignetteIndexEntry{Migration Guide}
+  %\VignetteEngine{knitr::rmarkdown}
+  %\VignetteEncoding{UTF-8}
+---
+
+```{r, include = FALSE}
+knitr::opts_chunk$set(
+  collapse = TRUE,
+  comment = "#>"
+)
+```
+
+In version 3.0.0 of {dv.loader}, significant changes have been made to improve the data loading functionality. The `load_data()` function, which was previously used for multiple file types, has been deprecated. In its place, a set of specialized functions have been introduced to handle specific file types more efficiently. This change aims to simplify the data loading process and make it more intuitive for users.
+
+The new functions introduced in version 3.0.0 are:
+
+1. `load_rds()`: Specifically designed to load RDS files (.rds)
+2. `load_sas()`: Dedicated to loading SAS data files (.sas7bdat)
+3. `load_xpt()`: A new addition to support loading XPT files (.xpt), which wasn't available in previous versions
+
+These changes bring several benefits:
+
+- Improved clarity: Each function clearly indicates the type of file it's meant to handle.
+- Enhanced performance: Specialized functions can be optimized for their specific file types.
+- Extended functionality: Support for XPT files has been added, expanding the package's capabilities.
+
+## Migration Steps
+
+To migrate from the deprecated `load_data()` function to the new specialized functions in {dv.loader} 3.0.0, follow these steps:
+
+1. Identify the file types you're working with:
+   - RDS files (.rds)
+   - SAS data files (.sas7bdat)
+   - XPT files (.xpt)
+
+2. Replace `load_data()` calls with the appropriate new function:
+   - For RDS files: Use `load_rds()`
+   - For SAS data files: Use `load_sas()`
+   - For XPT files: Use `load_xpt()`
+
+3. Update function arguments:
+   - Remove arguments `sub_dir`, `file_names`, `use_wd`, and `prefer_sas`.
+   - Specify the path to the file(s) using the `files` argument in the new functions.
+
+Test your code thoroughly to ensure all data is loaded correctly.
+
+## Example
+
+Let's walk through a detailed example of migrating from the old `load_data()` function to the new specialized functions in {dv.loader} 3.0.0. This example will demonstrate how to load SAS data files (.sas7bdat) using both the old and new methods.
+
+### Set up the data directory
+
+First, we'll set up our data directory `data_dir` using a sample dataset provided by the {dv.loader} package. The `data_dir` is the path to the directory containing the data files and it will be used in both the old and new methods.
+
+```{r}
+# Set the data directory
+data_dir <- system.file("extdata", package = "dv.loader")
+data_dir
+
+# List the files in the data directory
+list.files(data_dir)
+```
+
+### Load data using the old method
+
+In the old method, we need to set the environment variable `RXD_DATA` to the path of the data directory. The `sub_dir` and `file_names` arguments are used to specify the subdirectory and file names within the data directory. The `use_wd` and `prefer_sas` argument are optional and can be used to specify the working directory and the preference for SAS data files.
+
+```{r}
+# Set the RXD_DATA environment variable
+Sys.setenv(RXD_DATA = data_dir)
+
+# Load the data using the old method
+data_list1 <- dv.loader::load_data(
+  sub_dir = "pharmaverseadam",
+  file_names = c("adsl", "adae"),
+  use_wd = FALSE,
+  prefer_sas = TRUE
+)
+
+# Check the names of the data list
+names(data_list1)
+
+# Check the contents of the adsl data
+data_list1[["adsl"]]
+
+# Check the metadata of the adsl data
+attr(data_list1[["adsl"]], "meta")
+```
+
+### Load data using the new method
+
+In the new method, we need to specify the path to the file(s) using the `files` argument. File extension is not required in the file name to load the corresponding data. Unlike the old method, there is no need to set the environment variable `RXD_DATA`.
+
+```{r}
+# Set the files argument
+files <- file.path(data_dir, "pharmaverseadam", c("adsl.sas7bdat", "adae.sas7bdat"))
+files
+
+# Load the data using the new method
+data_list2 <- dv.loader::load_sas(files = files)
+
+# Check the names of the data list
+names(data_list2)
+
+# Check the contents of the adsl data
+data_list2[["adsl.sas7bdat"]]
+
+# Check the metadata of the adsl data
+attr(data_list2[["adsl.sas7bdat"]], "meta")
+
+# Remove the file extension from the names if needed
+names(data_list2) <- tools::file_path_sans_ext(names(data_list2))
+names(data_list2)
+```