Overview
The CDISC guidelines does not strictly suggest variable lengths so it is up to you to determine the optimal length for your submission.  A recommended strategy is to review all the data values and choose the length that is large enough to hold the longest value but then not too much longer than that.  The VARLEN tool accomplishes this task by finding the longest value and then rounding it to the nearest 10th decimal place.  It will then generate the code to update the length of your variables for the specified dataset.   

VARLEN Options
The VARLEN screen allows you to select the source data and related options which is used in updating the length of the dataset.  The data flow for this tool is shown here.

Source Data

CDISC Builder VARLEN

Updated Dataset with new lengths

The options available for selecting data and options for VARLEN are:

• Source Data - This is the location of the dataset that is going to be used to update variable lengths.
• Datasets - Source datasets that are used to for VARLEN.
• Preview - A preview of the first 100 observations of the data that is selected.
• Round - This will round off the length of the variable to the nearest 10th decimal place.  An option of 20 plus 10 to the rounding.

• Output - An optional output report can be generated in HTML format.

The VARLEN can be applied to many datasets at a time.