Project Management Life Cycles Explained

Explanation of life cycles in project management

By Lorian Lipton, PMP

When you dance, if you leave the wrong foot, you will never be able to recover. Unfortunately, the same thing can happen if you choose the wrong lifecycle approach for your project. With the wrong approach, you run the risk of cost overruns, long delivery times, and potentially a failed project. Fortunately, several project lifecycle approaches are available to help you successfully control and deliver your projects. This post will explain the current life cycle approaches based on the Project Management Knowledge Body Guide (PMBOK® Guide) – Sixth recently updated edition and how they affect project constraints.

What is the life cycle of the project?

The life cycle of the project contains all the phases that your project goes through from beginning to end (from cradle to grave). Some projects may have one phase, others may have more than one phase. The PMBOK® Guide – Sixth Edition defines the project life cycle as "the series of phases that a project goes through, from initiation to closure" (page 19). It seems simple enough.

What is a phase ?

According to the definition, each project consists of one or more phases, which are "a set of logically related project activities that result in the completion of one or more several deliverables "(page 20). The phases can be sequential (back to back), iterative (cyclic) or overlap (simultaneous in points). The more phases there are and the more overlap, the greater the risk of time, scope and cost constraints.

What is the life cycle?

The PMBOK® Guide directly calls two life cycle approaches: predictive and adaptive. Next, he subdivided the adaptive life cycle approach into several phases that they call the life cycles of development:


To help me decide which approach to use for a particular project, I focus on how the life-cycle approach manages project requirements, constraints, feedback from stakeholders, and feedback. resources.

What is the generic life cycle?

Rarely, nothing generic, but the PMBOK® Guide defines four generic phases in a life cycle:

Launch of the project
Organization and preparation
Realization of work
End of the project

(Figure 1-5 from page 18). The important things to know about this generic life cycle are:

Costs and staffing levels will continue to increase until they peak during the course of the work.
Risk and uncertainty will decrease with time
The cost of changes increases dramatically with time

"All projects can be mapped to the generic life cycle" (page 19), so make sure you know them if you are going to pass the PMP® exam.

Why am I interested in different types of lifecycle approaches?

When there was only one approach, Waterfall, we had to develop workarounds and try to contain and control everything in this fixed model (what a challenge). Today, with multiple approaches available, you can find the most flexible, cost-effective and fastest way to deliver (what a relief). Below, I detail the approaches mentioned in the PMBOK® Guide – Sixth Edition, but there are dozens of others that you can study and choose, each with its own advantages and disadvantages.

The life cycles explained

Predictive Life Cycle (Entirely plan-driven or falling water) – During the last 30 years of the last millennium (the 70s, 80s, and 90s ), the cascade approach was the gold standard for all projects. This is a fully planned approach where the three main constraints of the project (time, scope, cost) are all determined at a detailed level at the beginning of the project. You must know your needs, and the scope is fixed from the beginning. Each phase is then presented sequentially and carefully managed.

Over time, to allow for more accurate planning, the approach allowed for "incremental development" or "rolling wave planning" (page 185). Remember that scope and planning are two different things. The progressive development does not change the scope. It allows you to deploy the schedule in shorter passes. I measure all other approaches against the benefits and failures of this traditional approach (perhaps because it's the first one I've learned). The waterfall was great when I managed the highly controlled and predictive development of a new hard drive at IBM. The project lasted for years and did not require much stakeholder involvement (especially at the beginning and end or when we had scope changes that required approval). The disadvantage is that the water drop is quite rigid when it comes to changes at the end of the project, and therefore leads to significant cost increases when the recovery is necessary. That's why I believe people have started to come up with more adaptive approaches. But Waterfall is still a good life cycle approach if you have the development time and you know what you want to deliver. Do not neglect its benefits.

Iterative Lifecycle – With shorter delivery times and less clear requirements, we needed additional life cycle approaches to manage the changes more quickly and cheaply. We found that when you broke down complex, large projects into smaller phases (ie, cycles), it gave us more control (reduced risk and recovery costs). As its name indicates, you run the project in small iterations, which allows you to better define the requirements at the beginning of each cycle. The PMBOK® Guide (page 19) recommends that you set the scope at the beginning of the project, but change the time and costs after each iteration because you will understand them better.

The iterative approach is like a bunch of small cascade cycles with the client checking the work out of each cycle. This gives you more flexibility and a better opportunity to manage change and reduce risk. You detail the scope of the next phase when you are done with the previous one. I've used the iterative life cycle approach when developing software updates. My iterations lasted 3 or 4 months at a time as part of a longer project.

Incremental Life Cycle – Many times you will see the incremental approach grouped with the iterative. They are similar but also different. The approach of the incremental life cycle develops a product through the implementation of incremental steps that have predetermined deadlines . Each increment provides additional functionality for the product and is repeated until the final product is produced. As with the iterative approach, customers sign at each exit point. This approach is ideal when you want to prototyping and reduce the risk of change in the process.

Adaptive Life Cycle (change-oriented, alias Agile) – Everybody wants a fast development these days, so when you have to do a project quickly, Agile is the way to go. . This approach has been designed to manage changes and reduce inherent risks. The new PMBOK® Guide provides a complete appendix (Appendix A3: Agile & Lean Frame Overview, page 99) on the Agile / Lean approach. I strongly recommend that you read this appendix to better understand the concepts. Teams provide software updates in weeks rather than in a few months.

Adaptive projects are fast and time-limited with two critical success factors:

The client must be intimately involved in the process
You must be able to set the incremental requirements at the beginning of each iteration

If the requirements are not well known, such as when you develop a first application of this type, the adaptive approach works well.

In addition to sequential, interactive or superimposed iterations, they can also operate in parallel. But do not forget, especially when you go to the speed of light, that each iteration should always be a complete cycle of Plan, Develop, Evaluate and Learn. (A good project management process is all the more critical when you go fast.) Iterations usually last from 2 to 4 weeks at most.

To better understand all the concepts involved in Agile delivery, read the Agile Manifesto .

Hybrid Life Cycle – As its name indicates, the hybrid takes the best of all approaches. You can use a predictive approach for known project elements and an adaptive approach for elements that will appear over time. " Hybrid methodologies accept the fluidity of projects and allow for a more agile and nuanced approach to work," says Jason Westland.

Hybrid approaches are not new to project management, but they are definitely accepted as a way to solve life cycle problems in the 21st century. There is software on the market that allows you to merge approaches so you can manage different life cycle approaches in a single application. How is it treated?

Check out the next articles on tips for choosing the best approach in the project lifecycle. Do not hesitate to comment below, and I will do my best to answer your questions. Until next time, continue your good attitude.

About the Author

Lorian Lipton, PMP, provides project and program management consulting and training services to commercial, non-profit and government clients around the world through his company The Digital Attitude, LLC . She has successfully led complex projects related to risk, software and learning globally and excels in the development of project management methodology, performance metrics and standards. 39; education.

PMBOK® and PMP® are registered trademarks of Project Management Institute, Inc.

Content is copyrighted by Lorian Lipton, The Digital Attitude, LLC 2017.


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