Configuration Management (managing change)

Configuration Management (managing change)

Starter Questions. Which is more important? reliability and stability unrestrained progress Why is change potentially dangerous? What causes configuration problems? multiple developers multiple releases components used in multiple products changing requirements etc.

Change is inevitable. AND Change creates confusion. BUT, Confusion is NOT inevitable.

Outline for Tonight "Baselines" CM Repository and Config Tools CM Plan Much of this Software Configuration Management presentation is based on Chapter 27 of Pressman's Software Engineering: A Practitioners Approach 6th Edition

5 of 2 Goals of CM Identify Change Report Changes to people who Know Control Change Stability Need to vs Progress Ensure Change is Properly Implemented

What Changes? Software Code source code object code Tests Data Documents SRS designs project schedules test plans, test results

7 of 21 Key Concept: "Baseline" "A specification or product that has been formally reviewed and agreed upon, that there-after serves as the basis for further development, and that can be changed only through formal change control procedures." IEEE Std 729 Standard Glossary of Software Engineering Terminology

8 of 2 Baselines Establishment of a baseline is a milestone. Before that milestone, changes can be made informally. Once reviewed and accepted, the product becomes an established baseline. Everyone proceeds using that version, which is located in a central repository. Therefore, further change requires formal review, notifications, etc.

9 of 2 Baseline - Standard Change Process 1. Change Request is made (see next slide) 2. Request is Approved or Denied 3. "Check Out" the item(s) 4. Make Changes 5. Testing or Reviews formal review of design changes, regression testing of modules, etc 6. Review the Change Order 7. Notify all Dependencies 8. when baseline change will occur what changes were made to baseline "Check In" the new baseline

10 of 2 Template for Baseline Change Requests Name, Date, yadda yadda Type of change Goal of making the change Priority / Urgency Detailed description of the changes Expected Effects Timetable for making changes, testing, release, Estimated Costs

http://satc.gsfc.nasa.gov/GuideBooks/Image4.jpg

12 of 2 Version Numbering Item After Modify Test Plan Module 1 0.0.0 0.0.0 0.0.1 0.1.1 -- Build 1 Build 2 Release 1 (original version) -- 0.1.0 -- 0.1.0 -- -- 0.1.0 0.2.0 0.2.0 -- -- 1.0.0 1.0.0 Module 2 0.0.0 . 0.0.8 0.1.1 0.2.1 0.2.2 -- 0.2.0 -- 1.0.0

Question. How do we keep track of all these versions, dependencies among components, approval records, etc. etc. etc.? 1. Use Good CM Tools 2. Have a Sound CM Procedure

14 of 2 CM Repository - Common Jargon Configuration Item standard term for entities in the CMR CM Objects CM probably organized as object-oriented database Basic Objects Aggregate Objects

15 of 2 CM Tools - Necessary Features Versioning Dependency Tracking!!! Audit Trails!!! Reporting of Changes Supports the Change Rules Requirements Tracing Repository arranged as "basic objects" and "aggregate objects" Supports both Linear evolution and Trees

16 of 2 Parts of a CM Plan Process Elements Component Elements set of tools and file management system that enable access to and management of items Construction Elements collection of procedures that define approach to change management tools that automate the construction of software, test suites, etc. Human Elements

17 of 2 IEEE / ANSI 828 Standard for Software Configuration Management Plans 1. Introduction a) purpose b) scope c) definitions and acronyms d) references 2. Management a) organization b) SCM responsibilities c) interface control d) SCMP implementation e) policies, directives, procedures (naming conventions, version designations, problem report process) 3. SCM Activities a) configuration identification b) configuration control (change history, review authority, read/write control, member identification) c) configuration status accounting (status of change requests, status of approved changes, ) d) audits and reviews 4. Tools, Techniques, and Methodologies 5. Supplier Control 6. Records Collection and Retention

18 of 2 IEEE 1042 Guide to Software Configuration Management Defines terms such as baseline and version Discusses configuration management as a management discipline and its role in the engineering process Includes checklists of issues for sections of the SCMP (IEEE Std 828) Includes four complete examples of SCMPs

19 of 2 CM Audits % of unapproved changes % of Change Orders completed on schedule % of affected Configuration Items that were not checked % of properly documented Configuration Items number of CM Process Failures

Summary Change is inevitable. Baselines are milestones of a configuration item. Use a tool or set of tools to control change access control version tracking etc Adopt a Change Management Plan

Next Class Exam Two