The Project Management Professional (PMP)® and the PMI Agile Certified Practitioner (PMI-ACP)® certifications are two popular options for project managers who want to take their careers to the next level. While the PMP® certification and the PMI-ACP® certification are both earned after passing an exam, the primary difference between the two is the methods on which they focus. The PMP exam is focused on the Waterfall methodology, and subsequent project management approaches that support this methodology. In contrast, the PMI-ACP exam is entirely focused Agile practices.
Both of these project management certifications require expertise in two very different approaches. Before you can understand the difference between PMP and PMI-ACP certifications, you first need to learn about the methodologies on which these certifications are based – waterfall vs. Agile.
Waterfall Methodology
When you think of project management practices and schedules, you likely think of the waterfall method, on which the PMP certification is based. This is the most traditional method of project development and completion. One feature unique to this methodology is that it includes three distinct phases – planning, development, and testing.
- The Planning Phase - When used for software development, the waterfall approach relies heavily on upfront planning, laying out a path for the entire project, before any code is ever created.
- The Development Phase - In the development phase, sometimes called the build or execution phase, the actual code or product is developed. If any changes to the product design or original project plan are needed, they are normally handled with change requests during this phase.
- The Testing Phase - After the build phase is completed, products are tested during a comprehensive testing phase. Clients do not normally receive the finished product until all work on the project has been completed and delivered.
Waterfall projects, due to their heavy reliance on clearly defined project plan, make them highly predictable. They generally have a specified completion date by which the client can expect project delivery. When you use the waterfall approach to manage your projects, you benefit from having clear expectations established prior to project launch, and a clear outline of milestones by which you can gauge project progress.
The waterfall approach was first developed for the manufacturing industry. However, today it is used by companies all over the world in a wide variety of industries. The waterfall approach is ideal for project teams who have:
- Completed a similar type of project in the past
- A desire to establish project scope before they begin work
- Experience with accurately estimating resources and cost of projects
Agile Methodologies
In contrast to the chronological and highly planned development processes with the waterfall approach, Agile methodologies feature iterative development phases, with each version of a project building on the previous one.
- Backlog - Projects and their features are broken down into manageable tasks with the intention of completing the highest priority tasks first. The objective of this project management approach is to complete the baseline version of a product that can be launched as quickly as possible. Then, tasks are completed to create a new, workable iteration of a project each sprint.
- Sprints - Sprints are short periods of time (generally about two weeks or a month) in which a new iteration of a project is started and completed. Each sprint is independent of the previous one, as products and their features are designed, constructed, and tested all within a single sprint. Team members commit to the tasks they plan on completing at the beginning of the sprint.
- Delivery - After the sprint ends, features are presented to the client as operational deliverables. Because clients are receiving completed features at the end of each sprint, they see constant progress.
Agile methodologies were created for the software development space with the goal of prioritizing high value work that can be completed in a fast-paced environment. While other project management approaches like waterfall rely on a rigid plan and scope to ensure success, Agile use flexibility to adapt to needed changes and ensure project success. The rapid delivery of high quality products and their feature is ideal for companies in the software development space, where they can gain a competitive advantage from fast product launches. Agile is ideal for projects in which:
- A client frequently changes direction
- A product needs to be launched quickly
- There is uncertainty about the cost and timeline of a project
Waterfall vs. Agile: What’s the Difference?
Now that you know more about the structure of the methodologies that PMP and PMI-ACP certifications focus on, look at a few areas in which waterfall and Agile project management approaches differ.
- Planning - Both waterfall and Agile approaches do have comprehensive planning stages. However, these stages have very different impacts on the project. With waterfall planning, the plan for the entire project is outlined before the project even begins. With Agile, a planning session occurs before the start of each sprint to outline the tasks that are expected to be completed during that sprint. Agile planning occurs on a much smaller scale than waterfall planning.
- Build - Agile projects are completed with an iterative process. An initial iteration of a project is built upon with each subsequent sprint, and many team members may be building and developing different aspects of a project simultaneously. Waterfall projects take a more linear approach to building a project. Only when one task is started and completed can the next task begin.
- Changes - In the waterfall approach, change can be an uphill battle. Because a comprehensive plan is outlined from the beginning of a project, any changes, even minimal ones, will impact the entire project plan. Agile is designed to be more flexible in terms of change. Since projects are developed within the confines of a sprint, any changes can simply be included in the next sprint. Clients have greater opportunity for feedback and change, as they see completed deliverables at the end of each sprint.
- Delivery - With the waterfall approach, clients only receive a deliverable when it is totally completed. They receive a final product based on the initial plan after it is completely built. Agile, on the other hand is an iterative approach. Clients will receive a completed deliverable at the end of each sprint, but the product is constantly developing as new features are added with each sprint. For example, if you are developing a website with Agile methods, the highest priority page will be completed first, with the highest priority features included. Pages that are not pressing can be created in later sprints.
- Testing - To ensure a high quality product is being delivered, testing newly created features is essential. Because the waterfall approach occurs in distinct phases, testing only occurs once the product is completely built. In contrast, teams using the Agile approach regularly test their products as each iteration is developed.
Earning either the PMI-ACP or the PMP certification is a smart move for your project management career, but you should really consider the differences between these two approaches before you pursue a certification. Waterfall project management isn’t right for every team, and Agile isn’t either. Think about the type of projects you want to be involved in moving forward, and which approach is best suited for your organization.
