Analytics Software & Solutions


Strong Tower Solutions offers a comprehensive versioning solution for SAS code and other objects. The solution aids in tracking of changes to better meet an organization’s internal change policies and to meet regulatory requirements.

The Challenge

Trying to maintain a record of all the changes that SAS programs undergo as part of any development effort without a source code management system can be a daunting task. Developers are often faced with either the time-consuming effort of using convoluted change management procedures or bypassing the detailed versioning of their code for expediency sake. Either way, valuable information about the history of SAS programs is either lost or not maintained in a cohesive, methodical fashion. If a record of the changes exists, it is frequently only because complex processes, procedures, and policies must be adhered to.

Without tools to help manage the versioning process, costly manual procedures must be used to keep a record of changes. Often overlooked with any recording mechanism is not only what has changed, but who made the change and when it was performed.



The Solution

  • A low cost and proven solution built using a commercially available software package
  • Pre-built templates for Standard Operating Procedures to document and accelerate deployment


Given that SAS is widely utilized to support clinical trials, and subject to regulatory scrutiny, it is imperative that accurate records be maintained in the development life cycle of SAS programs. 

STS has put together an offering that addresses the shortcomings or absence of manually maintained change control methods.  It is based on an industry recognized and time-tested source control management system called SubVersion, or SVN for short.   SVN stores all data consistently in a central data repository.  SAS programs and other data elements and files are “checked-out” when changes need to be made.  Once changes have been tested and signed-off, the new version of the program or file is “checked-in” along with a record of the change and who made it.  Other than the check-out/check-in process, changes to the programs or other data is done exactly as now.  The SAS Version Control solution does not add needless overhead or create undue burdens to developers.

  •  SubVersion server stores all programs and files in a central repository.  It also controls access to the data and maintains the various revisions along with their history.
  • SubVersion client interacts with the server to extract objects from the repository and controls the updating of those objects back into the repository. The SVN client is called TortoiseSVN which integrates directly into Microsoft Windows File Explorer.


Using a version control system adds discipline to the process by which SAS programs and other files related to a project or clinical trial are maintained and stored.   Consistency can be established in how programs and other data is stored, accessed, retrieved, and updated. 

The importance of having accurate records and an audit trail of changes is becoming increasingly important in today’s environment which requires a complete accounting of work performed.    Our Version Control solution provides this demanding level of accountability.

Key to all of this, however, is a system and methodology that minimizes infringing on the development process.  That is, any source control management system should not become so “heavy” that it creates undue burdens to developers.  Our Version Control solution is streamlined to minimize the impact of working day-to-day with SAS programs and other files.

FDA Title 21 CFR Part 11 Compliance

The use of SubVersion in SAS programming environments provides a mechanism by which regulatory compliance can be achieved, specifically for portions of section 11.10 of the regulation, which deal with audit trails, code and data revisions. 

The STS Advantage

The version control capabilities provided by Subversion are freely available, but it is only a tool.  The benefit of that tool is in how it will be implemented and used.  STS provides the installation, configuration, and implementation services to help an organization get started with version control and get them up and running quickly.  STS does this by:

  • Working with the organization to develop a comprehensive list of requirements
  • Tailoring SVN to meet those requirements
  • Develop processes and procedures for how version control should be done
  • Plan and execute a pilot to test the accuracy of the process and procedures
  • Assist in organizing the information, programs and files in an optimal and consistent way for loading into SVN
  • Helping to transition from pilot into full production
  • Offering training to allow developers to become effective and efficient in the shortest amount of time possible


  • Complete record of all changes, who made them and when they are made
  • Audit history in a consistent format
  • A turn-key offering that can be customized to suit an organization’s particular needs
  • Can be used for any type of file or data type
  • Enforces standards and practices to create a consistent environment
  • Bring new people on board with minimal indoctrination


  • Maintain all SAS programs in a central repository
  • Records who made changes and when they were made
  • Extends to non-SAS objects; can be used with any type of data or file
  • View precise differences between versions of SAS programs
  • Allows for multiple people to work on the same object without fear of stepping on each other or losing changes; ability to resolve code conflicts easily
  • Ability to easily revert to an earlier version of the same program or file
  • Create multiple branches of the same sets of programs to support parallel streams (i.e. production, Quality Assurance, and development)
  • User controls that can limit who can access what objects in the repository
  • Integration with central authentication systems (e.g. Windows Domain Authentication)
  • Support for multiple, replicated repositories for redundancy

You Decide How It's Implemented

STS can work with you to determine the most advantageous way to implement SubVersion.  We provide you a framework and configuration as a starting point based on our experience with SAS and work with other life science customers. It can be installed on your hardware running on your choice of Windows or Linux operating systems.  Alternatively, it can be hosted with our partner, Validated Cloud, whereby you are not burdened with maintaining the SVN server. We can also provide ongoing support in a managed services model thereby providing you complete turn-key support.

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