1. Assuring the quality of software maintenance components
Presentation 11
Assuring the quality of software
maintenance components
Introduction
The foundations of high quality maintenance
Foundation 1: software package quality
Foundation 2: maintenance policy
Pre-maintenance software quality components
Maintenance contract review
Maintenance plan
Maintenance software quality assurance tools
SQA tools for corrective maintenance
SQA tools for functionality improving maintenance
SQA infrastructure components for software maintenance
Managerial SQA tools for software maintenance

2. Corrective maintenance Functionality improvement maintenance
Software maintenance
components
Software maintenance
Corrective maintenance
Adaptive maintenance
Functionality improvement maintenance
Perfective maintenance
Preventive maintenance
23-24%
54-60%
17-22%
+ User support service

3. Types of Maintenance
Corrective maintenance is concerned with fixing errors that are observed when the software is in use
Adaptive maintenance is concerned with the change in the software that takes place to make the software adaptable to new environment such as to run the software on a new operating system. 
Perfective maintenance is concerned with the change in the software that occurs while adding new functionalities in the software. 
Preventive maintenance involves implementing changes to prevent the occurrence of errors.

4. User’s difficulties Software failure Documentation failure
Incomplete, vague or imprecise documentation
User’s insufficient knowledge

5. Software package quality
Foundation 1:
Software package quality
Quality factors of high impact on software maintenance
Quality factor
Corrective maintenance
Adaptive maintenance
Functionality improvement maintenance
Correctness – Output
High
Correctness - Documentation
Correctness – Coding qualification
Reliability
Maintenability
Flexibility
Testability
Portability
Interoperability

6. Foundation 2: Maintenance policy
Version development policy
Sequential version policy
Tree version policy (branching and new version rules)
Change policy (permissive/balanced)

7. Maintenanace contract review
Pre maintenance SQA components
Maintenanace contract review
Customer requirements clarification
Review of alternative approaches to maintenance provision
Review of estimates of required maintenance resources
Review of maintenance services to be provided by subcontractors and/or the customer
Review of maintenance costs estimates

8. Pre maintenance SQA components
Preparation of a
Maintenanace plan
A list of the contracted maintenance services (external and internal customers)
A description of the maintenance team's organization
A list of maintenance facilities
A list of identified maintenance service risks
A list of required software maintenance procedures and controls
The software maintenance budget

9. SQA tools for corrective maintenance
Contractor-Subcontractor contract (for outsourcing maintenance services)
- Procedures for handling maintenance calls
- Full documentation of the service procedures
- Availability of records
- Certification for the contractor
- Quality-related conditions

10. SQA tools for functionality improving maintenance
Project life cycle tools (reviews & testing)
Tools are also implemented for large-scale adaptive maintenance tasks.

11. SQA infrastructure components for software maintenance
Maintenance procedure and work instruction
Supporting quality devices
Training and certification of maintenance teams
Preventive and corrective actions
Configuration management
Maintenance documentation and quality record control

12. Managerial SQA tools for software maintenance
Performance controls for corrective maintenance services
Quality metrics for corrective maintenance
Cost of software maintenance quality

13. Cost of software maintenance quality
Cost of prevention
Cost of appraisal
Cost of managerial preparation and control
Cost of internal failure
Cost of external failure
Cost of managerial failure