1. Software Engineering Lecture 14 - Software Lifecycle 2

2. Software Development Process

3. Agenda
Configuration Management
Deployment
Maintenance

4. Software Configuration Management (SCM)
Changes to requirements drive the design
Design changes affect the code

5. Motivation What if a fully tested program doesn’t work?
What if a difficult bug that was fixed reappears?

6. Without control Simultaneous updates Shared code Common code Versions
Problems
Leads to wasting an enormous amount of time

7. Control the system To answer the questions
What is my current software configuration?
What is its status?
How do I control changes to my configuration?
What changes have been made to the software?
Do anyone else’s changes affect my software?
What tests go together with this version?

8. Configuration Management Overview
Initial development
Establish / Update Baseline
Validate Baseline
Baseline
Changes
Requirements / Design / Use
Authorize change
Implement change
Validate change
Approve change

9. Change Request Form

10. Configuration Control
Only one official copy of the code
Baseline
Not the same as version management
Changes to the baseline must be approved

11. The version confusion
“The user-interface crashes when I press this button”
“But you told me you added this feature… I don’t see it”
“There is an interface mismatch between these components”

12. Versioning Revisions Branches Merge Trunk (subversion) = Master (Git)
saved changes
Branches
the main projects is branched to enable simultaneous development
Merge
a point where branches are merged to form a new baseline
Trunk (subversion) = Master (Git)
The main branch of the project
Baseline = Labels = Tags
An approved version for all to work on
Checkout, Commit, Conflict - Resolve, Delta compression (only retain the differences between successive versions of files), Repository where the current historical data is stored, working copy (local copy)

13. Versioning In some cases:
Odd-numbered versions for development releases
Version 1.0 as a milestone
major.minor[.build[.revision]]
Or major.minor[.maintenance[.build]]

14. Tools Versioning / Change management tools Bug tracking CVS Subversion
Git
Bug tracking
Bugzilla
Mantis
Redmine

15. Release Management
Deployment

16. Common Release Problems
Take too long – impacts revenue
Unpredictable – impacts dependent plans
Poor quality – impacts support
Not useful – impacts revenue
Contents unplanned – impacts integrity
Contents uncontrolled – impacts reliability
Overlooked distribution/installation – impacts support
Cowham, Robert. “Release Management – Making it Lean and Agile” CM Crossroads, Aug 16,

17. The Challenge Time to Market vs Features vs Quality Time to Market
Only one top priority
Balance – don’t ignore the other two
Release criteria reflect priorities
Product development methodology supports priorities: concurrent engineering, test-first development, prototyping
Time to Market
Features
Quality

18. Types of Releases
Major = significant new features, product launch, planned, pull, annual
Minor = small new features, backwards compatible, planned, pull, semi-annual
Patch = collection of bug fixes, planned, pull, quarterly
Emergency = Urgent bug fix, harmful if not fixed, unplanned, push, as needed

19. Attributes by Release Type
Features/Functions
Bugs
Cost
Urgent
Scheduled
Backwards Compatible
Major Y
(new)
Minor
Y (upgrade)
Patch
Fix

20. Release Process Define Content Assign Version Plan Release Build
Package
Deploy
Test
Control Change
Assess Readiness
Release
Iterate

21. 1. Define Content Golden Build (software) Documentation
Training materials
Marketing collateral
Internal documents
Customer Notification
Release Notes

22. 1. Define Content: Must and Nice
Disp ID
Severity
Pri
Description
Nice
41928
enhancement P3
Performance - Publish: loadSiteLite() to replace loadSite()
59439
trivial P4
Misalignment of Editable site and Proof site sections on Manage site screen once the actor checks Lock-site checkbox.
59929
minor P5
Error message:Get A Quote form:The listed items in error message may need some order; by logical or by alphabetic
57954
major P2
Only Ford Make is displayed in 'Quick Quote Form' : GM Design
59368
Masthead descenders are being chopped off in Klamath_B_Dst design
57019
Can't tell mouse over selection from current page selection in nav
59726
Design Celandine: Titles (Header) for static pages are not bold as those for dynamic pages
60108
Misalignment of footer in Hours and directions page-Celandine designs
Must
64793
create new Saab luxury design and homepage
64796
create new Land Rover luxury design and homepage

23. 2. Assign version
Version is a unique identifier for the product state as of a certain point in time. Not all versions are released. Versions are sequential.
Versioning Schemes relate to release types, product management, and configuration management:
Major.Minor.Patch.Fix, e.g. 1.0, 1.1, 1.1.2,
Major.Feature.Patch, e.g. 1.0, 1.1, 1.1.2
Major.Feature.Patch.Build, e.g

24. 3. Plan Release Dependencies Customer commitments Revenue recognition
Resource availability: people, environments
Introducing too much change at once
Stabilizing between releases
Organizational capability

25. 3. Plan Release: Milestones
Scope Freeze
9/7
COMPLETE
Functional Freeze
9/17
Functional Test Complete
9/30
Code Freeze
10/1
Regression Test Complete
10/13
Golden Build
10/8
Performance Test Complete
Mock Deployment
10/12
FAILED
10/14
Deployment Plan Review
10/15
Go/No-Go
COMPLETE – GO
Executive Approval
COMPLETE-APPROVED
RELEASE

26. 4. Build Build (What) Visibility (Who) Frequency (When) Purpose (Why)
Private System Build
Individual Developer
One or more times per change task
Provide feedback to the developer of the changes just implemented in the private workspace.
Integration Build
Whole Development Team
After each change task and/or one or more times per day (e.g. Nightly)
Integrates the latest changes in the repository and runs automated tests against the release providing feedback to the development team.
Release Build
Independent Test (QA or V&V) Team and Customers
At the end of each iteration/release
Packages release for distribution to the development team’s customer.
Appleton, Brad. “Agile Build Promotion: Navigating the Ocean of Promotion Notions”, CM Crossroads, September

27. 5. Package
Create the release package containing all release deliverables
File: tar, .zip, .exe, .msi
Medium: CD-ROM, Web, App-store, etc.
Bill of Materials lists what’s in the package
Final release package is “golden build”
December 6, 2004

28. 6. Deploy Deployment Plan Install Team Deployment Plan Review
Contact List

29. 7. Test Plan ahead for test environments Execute Test Plan
Functional test: does it function as required?
Regression test: did old bugs reappear?
Performance test: does it perform within acceptable limits?
Reliability test: does it function consistently over time?
Stress test: does it function consistently under volume?

30. 8. Control Change Baseline scope, requirements, design
Accommodate controlled change
Allow change, it’s reality
Change requests
Change request decision (approve, reject, defer)
Change Control Board (CCB)
Cross-functional representation
Impact analysis
Business drivers

31. 9. Assess Readiness Release Criteria define “done”
Defined Deliverables
Features: Must Have vs Nice to Have
Quality: test results, metrics
Schedule: time-to-market criteria
Objective, quantifiable criteria preferred
Organizational Readiness
Support, Training, Marketing, Sales
Acceptable Risk

32. Assess Readiness: Metrics
Common metrics: fix rate, find rate, defect density, rate of change
Example: find rate vs fix rate
Stability reached at week 35 of testing, when defects fixed exceeds defects opened.

33. 9. Assess Readiness: Go/No-Go
Release Readiness Assessment
Are all release criteria equal?
Can any criteria be waived?
Go/No-Go
Formal sign-off by stakeholders
Meeting, vote
Recommendation by Release Manager
Executive Approval

34. 10. Release Formal release by Configuration Mgmt
Deploy to Production or Distribute to Customer

35. What’s in the release? Getting your program ready for market
Help documents
Executable file
Icon library
License Agreement
Code Obfuscation
Trial Version
Install Wizard
Uninstall Program

36. Maintenance

37. What maintainers do
Alain Abran and James W. Moore, Executive Editors. Guide to the Software Engineering Body of Knowledge - SWEBOK®. IEEE Computer Society, ISBN

38. Types of Maintenance Corrective Maintenance Adaptive Maintenance
Perfective Maintenance
(Preventative Maintenance)

39. Corrective Maintenance
Focuses on fixing defects, ie, fault repair
It is a reactive process
i.e. defects generally need to be corrected either immediately or in the near future
Defects
refer to the system not performing as originally intended or as specified in the requirements
17% of maintenance is correcting faults

40. Adaptive Maintenance
It includes all changes to meet the evolving needs of the user and the environment
i.e. modifications to a system to cope with a changing environment, eg changed hardware, operating system
18% of maintenance is change to adapt to a new environment
It includes work to enhance a system’s functionality
i.e. relates to changing a system when requirements change due to organisational or business changes
The scale of this maintenance is often greater than for other types of maintenance
65% of maintenance is new requirements

41. Perfective Maintenance
It includes all efforts to improve the quality of the software
It includes restructuring code, creating and updating documentation, improving reliability or efficiency, improving performance
Maintenance work in the above categories is often performed concurrently

42. What maintenance is Re-engineering Refactoring Bug-fixing
Adding features
Porting to new environments
Improving quality attributes
Etc.

43. Summary Larger systems require more control
Without control we end up wasting time
We need to be able to track and control changes
Release management
What should be included in the release?
Maintenance
Less work if we did it right from the start
Documentation, versioning, architecture design, plan ahead, etc.