Overview
This activity determines the mechanisms that will be used to ensure all software products under software configuration management (SCM) are backed up and restorable, and the procedure for product restoration.
Roles and Responsibilities
The SCM manager develops the backup and restore procedures for the project.
The system administrator supplies information pertaining to system backup capabilities.
Controls
The software engineering environment, documented in the Establishing a Software Development Environment section of the Software Development Plan (SDP) (see Appendix E).
Inputs
The software product list of products to be placed under SCM.
Any additional information on the system’s backup capabilities from the system administrator.
The completed Software Configuration Management Needs Form (see Appendix C).
The Preparing for Software Transition section of the SDP, which documents the software products to be released to the customer.
Procedures
1) The system administrator gives the SCM manager a high-level briefing on the software engineering environment (defined in the Establishing a Software Development Environment section of the SDP) and the platforms being used, including the environment’s backup and restore capabilities. The system administrator also describes the backup methods that have been used in the past (e.g., tape or floppy disk).
2) The SCM manager answers the following questions based on personal knowledge of the project and the software engineering environment.
How many versions of each software product must be supported at any given time? The Preparing for Software Transition section of the SDP can aid in identifying the various versions that will be released. Each released version should be restorable and, thus, must be backed up. If possible, backup copies should be kept at a location separate from the development site.
Are commercial off-the-shelf (COTS) products (e.g., Booch components) needed to perform a product restoration? If so, the SCM manager carefully notes the version of each of these items, and requires that a backup of each be kept at a separate location.
Can restoration be performed using only tape or floppy disk backups? Where can these be stored? Are special instructions needed to restore each product? What is the life span of the recording media?
How long shall the development team be able to perform a product restoration (e.g., x years beyond the delivery of a product or the life of the contract plus y years)?
How long shall daily or weekly backups be kept?
Is it possible to perform incremental backups instead of full backups?
3) The SCM manager uses the information obtained from the system administrator, the answers to the questions in step 2, and personal knowledge of the system’s capabilities to plan the backup and restoration of the software products. The SCM manager reviews the software product list to verify that each of the software products being placed under SCM can be restored. It should always be possible to restore any version of any software products released during the life of the project.
4) The system administrator aids the SCM manager in determining the backup schedule. The completed Software Configuration Management Needs Form suggests a backup frequency; however, this may be tailored for each software product. The SCM manager reviews the feasibility of the suggested backup frequency with the system administrator, and determines how often, when, and how backups should be done. Backups may be scheduled daily, weekly, or bi-weekly. Each backup may be full, delta, or incremental. Factors to consider in defining a backup schedule include: project schedules, media cost, machine and network availability, and system administrator availability. It is important to realize that there may be changes to software, test cases, test data, schedules, and components at any time in a development life cycle.
5) The SCM manager documents the backup and restore procedures in the Packaging, Storage, Handling, and Delivery section of the SCM Plan (SCMP) (see Appendix E).
Outputs
The backup and restore procedures which are documented in the Packaging, Storage, Handling, and Delivery section of the SCMP.