Cycle

Definition

Cycle

the top-level stage consisting of one or more related phases

Classification

As illustrated in the preceding figure, cycles are part of the following inheritance hierarchy:

• Type: Concrete
• Superclass: Stages with Duration
• Subclasses:
  • Business Engineering Cycle
  • Life Cycle
  • Development Cycle
• Example Instances:
  • The traditional Waterfall development cycle, which equated the major engineering activities (e.g., requirements engineering, architecting, design, implementation, integration, and testing) into sequential, non-overlapping phases.
  • The Spiral cycle (from Barry Boehm), which emphasizes iterative and incremental requriements engineering for risk management.
  • The Fountain development cycle from the MOSES development method, which provided a nice visual metaphore for the iterative and parallel aspects of the development cycle.
  • The iterative, incremental, and parallel IIP development cycle, which is typically used on modern object-oriented development projects.

Responsibilities

The typical objectives of a cycle are to:

• Provide an overview to the project as a whole in terms of its phases.
• Provide overall organization to its activities and milestones.
• Support top-level scheduling of activities, personnel, and resource acquisition.

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
• Life Cycle:
  1. Initiation Phase
  2. Construction Phase
  3. Initial Production Phase
  4. Full Scale Production Phase
  5. Delivery Phase
  6. Usage Phase
  7. Retirement Phase
• Development Cycle:
  1. Initiation Phase
  2. Construction Phase
  3. Initial Production Phase
  4. Full Scale Production Phase
  5. Delivery Phase

Cycle Characteristics

The OPF Cycles have the following characteristics:

• Iterative
• Incremental
• Parallel
• Contratual
• Time-Boxed

Guidelines

• General Guidelines:
  • Different cycles contain different phases, depending on the mission of the endeavor.
  • Cycles and phases can be combined or decomposed depending on the need for these stages to better map to engagements and contracts between the various organizations.
• Usage Guidelines for using the OPEN Process Framework (OPF) to produce a process containing a project-specific cycle:
  • 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 set of cycles.
    • Choose the reusable cycle in the repository to use based on the type of project and the types of work products to be produced. For example, a business engineering project would only have the business engineering cycle, whereas an application development project would use the application development cycle.
    • Document the cycle selected in the project-specific process description document.
  • Extension Guidelines for extending the repository with a new cycle:
    • Ensure that each new cycle is cohesive in terms of its definition and objectives.
    • Ensure that each new phase is internally consistent:
      • The cycles’s phases are consistent with the cycle’s name and objectives.
    • Ensure that each new cycle is externally consistent in that its objectives do not inadvertantly overlap the objectives of existing cycles.
    • Ensure that each new cycle is adequately documented using the standard topics.
  • Tailoring Guidelines for modifying a selected cycle 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 phases as appropriate.
    • Document your tailoring decisions in the description of the project-specific process.