Software Maintenance

Definition

Software maintenance is the activity consisting of the cohesive collection of all tasks that are primarily performed to incorporate minor fixes and enhancements into a software after deployment for use by the user organizations (i.e., between development projects to produce major new versions).

Goals

The typical goals of software maintenance are to:

• Ensure correct functioning of the software until the next version is deployed.

Objectives

The typical objectives of the software maintenance subactivity are to:

• Perform adaptive maintenance by making minor modifications due to:
  • Business changes (e.g., reengineering, competition, reorganization, business-internal politics).
  • Legal changes (e.g., new legislation, new regulations).
  • Technology changes (e.g., hardware, software, communications, technology standardization, commercial packages).
  • Physical changes (e.g., reconfiguration of data center, transfer to new locations).
  • Personnel changes (e.g., changes to the users, user management, information technology staff).
• Perform corrective maintenance by correcting minor defects in the software.
• Perform perfective maintenance by making minor improvements in correct software (e.g., refactoring).

Examples

Kinds of software maintenance include:

• Adaptive maintenance, which is maintenance performed to make the software usable in a changed environment.
• Corrective maintenance, which is maintenance performed to fix minor defects in the software.
• Perfective maintenance, which is maintenance performed to improve a merely adequate quality factor such as maintainability, performance, understandability, etc.

Examples of software maintenance include:

• Maintenance of commercial-off-the-shelf (COTS) software
• Maintenance of government-furnished-equipment (GFE) software
• Maintenance of internally-developed reusable software

Preconditions

Software maintenance typically may begin when the following preconditions hold:

• The delivery phase has completed.

Completion Criteria

Software maintenance is typically complete when the following postconditions hold:

• The maintained version of the software has been either removed from service or replaced by a new version.

Tasks

Software maintenance typically involves the maintenance team performing the following maintenance tasks in an iterative, incremental, and parallel manner:

• Maintenance Planning
• Defect Identification
• Defect Analysis
• Defect Correction
• Defect Status Reporting

Environments

Software maintenance is typically performed using the following environment(s) and associated tools:

• Production Environments:
  • Client Environment
  • Contact Center Environment
  • Content Management Environment
  • Data Center Environment
• Tools:
  • Configuration Management Tool
  • Test tool
  • Defect tracking tool

Work Products

Software maintenance typically results in the production of the following work products:

• Maintenance Plan
• Updated system data, hardware, or software software.
• Updated developer or user documentation

Phases

The software maintenance activity tasks are typically performed during the following phases:

• Business Strategy: Not Applicable
• Business Optimization: Not Applicable
• Initiation: Not Applicable
• Construction: Not Applicable
• Initial Production: Ongoing
• Full-Scale Production: Ongoing
• Delivery: Ongoing
• Usage: Ongoing
• Retirement: Not Applicable

Guidelines

• Software maintenance depends on the maintainability of the software being maintained:
  • Adaptive maintenance depends on adaptability and extensibility.
  • Corrective maintenance depends on correctability.
  • Perfective maintenance depends on maintainability.
  • Preventative maintenance depends on correctability and maintainability.
• Major modifications do not occur during maintenance but rather during the next development cycle.
• This activity is documented using the typical configuration for large projects. It is intended to be configured (i.e., instantiated, extended, and tailored) to meet the needs of specific projects.
• The preconditions of this activity should be the union of the preconditions of its constituent tasks.
• The completion criteria for this activity should be the union of the postconditions of its constituent tasks.