Serial life cycle initiatives expect to take advantage of high certainty around firm requirements, a stable team, and low risk. As a result, project activities execute in a linear manner, as shown in Figure 1. Figure 2 depicts the V-model serial life cycle for software development, similar to what Winston Royce originally proposed (and recommended against) in his 1970 paper. In the V-model the test phase is depicted as multiple stages and there are clear indications of what each testing activity validates (for example, Integration Test validates your architecture).
Figure 1. Example of a serial life cycle.
Figure 2. The V-model life cycle for software development.
To achieve this approach, the team requires detailed plans to know what to deliver and how. These projects succeed when other potential changes are restricted (e.g., requirements changes; project team members change what the team delivers). Team leaders aim to minimize change for a serial project.
By emphasizing a departmentally efficient, linear sequence of work, serial projects do not typically deliver business value until the end of the project. If the serial project encounters changes or disagreements with the requirements, or if the technological solution is no longer straightforward, a serial life cycle project may incur unanticipated costs.
For more details on selecting and using serial life cycles, see PMBOK Guide 7th Edition 2.3 Development Approach and Life Cycle Performance Domain.
How Disciplined Agile (DA) Helps Serial Life Cycle Teams
Many of the DA principles, promises and guidelines can be used with any life cycle. For instance. the DA principle Be Pragmatic supports using whatever approach or life cycle necessary to achieve the desired outcomes.
The DA principle “Be Awesome” deals with personal attitudes and supporting others which applies to any life cycle. So too are Choice is Good, Enterprise Awareness and Create psychological safety and embrace diversity, amongst many others.
For all life cycles, DA provides a robust set of choices and tools to help teams and organizations be more effective.
February 2022