Phase

Definition

Phase

a kind of stage with duration that forms a major logical partition of a cycle, whereby a phase:

• Consists of one or more builds.
• Is punctuated by one or more milestones.

As illustrated in the preceding figure, phase is part of the following inheritance hierarchy:

• Type: Abstract
• Superclass: Stage with Duration
• Subclasses:
  • Business Engineering Phase:
    1. Business Strategy Phase
    2. Business Optimization Phase
  • System/Application Phase:
    1. Initiation Phase
    2. Construction Phase
    3. Initial Production Phase
    4. Full Scale Production Phase
    5. Delivery Phase
    6. Usage Phase
    7. Retirement Phase

Responsibilities

The typical responsibilities of phases are to:

• Decompose cycles into manageable and cohesive time intervals.
• Provide a natural organization to development and life cycle.
• Enable the developer organization to divide and conquer the development process.

Cycles And Phases

As illustrated in the preceding figure, the OPF predefined cycles contain the following phases:

• Business Engineering Cycle:
  1. Business Strategy Phase
  2. Business Optimization Phase
• System/Application Life Cycle:
  1. Initiation Phase
  2. Construction Phase
  3. Delivery Phase
  4. Initial Production Phase
  5. Full Scale Production Phase
  6. Usage Phase
  7. Retirement Phase
• System/Application Development Cycle:
  1. Initiation Phase
  2. Construction Phase
  3. Initial Production Phase
  4. Full Scale Production Phase
  5. Delivery Phase

Guidelines

• General Guidelines:
  • It is important to clearly differentiate phases and activities, which were confused and incorrectly equated in the classic waterfall development cycle.
  • Phases can be combined or decomposed depending on the need for them to better map to engagements and contracts between the various organizations.
  • When only a single copy of the application is constructed, then phases should not overlap nearly as much as activities and tasks do.
  • The delivery and usage phases typically overlap the initial and full scale production phases.
• Usage Guidelines for using the OPEN Process Framework (OPF) to produce a process containing project-specific phases:
  • Creation Guidelines for creating a project-specific process from the OPF:
    • Because OPF is a general (and therefore relatively complete) framework, its class repository contains a relatively complete number of phases.
    • Choose the reusable phases in the repository to instantiate based on the type of project and the types of work products to be produced. For example, a business engineering project may only have the business strategy phase, whereas an application development project may either include the initiation, construction, and delivery phases or else be broken up into two subprojects, the first containing only the initiation phase and the second containing the construction and delivery phases.
    • The construction phase is sufficient if only a single application is being constructed. However, when large numbers of the application are to be produced, a full scale production phase is needed. Typically, a small number of systems is developed during an initial production phase in order to identify and solve potential problems prior to the begin of the full scale development phase.
    • Document the selection of phases in the project-specific process description document.
  • Extension Guidelines for extending the repository with a new phase:
    • Ensure that each new phase is cohesive in terms of its definition and objectives.
    • Ensure that each new phase is internally consistent:
      • The phase’s objectives are consistent with the phase’s name.
      • The phase’s milestones are consistent with the phase’s objectives.
    • Ensure that each new phase is externally consistent in that its objectives do not inadvertantly overlap the objectives of existing phases.
    • Ensure that each new phase is adequately documented using the standard topics.
  • Tailoring Guidelines for modifying a selected phase to meet the specific needs of a project:
    • Tailoring can happen at any time during the project:
      • At the beginning of the project when the project-specific process is produced.
      • During the process as situations change and lessons are learned.
    • Modify the definition as appropriate.
    • Add, modify, or delete objectives as appropriate.
    • Add, modify, or delete milestones as appropriate.
    • Document your tailoring decisions in the description of the project-specific process.