Many people are confused over the difference between a project management method and the System Development Life Cycle. Some believe a project management method is a subset of the SDLC and some believe the inverse, that the SDLC is a subset of a project management method. The truth lies somewhere in between. In terms of importance to a project, the SDLC and a project management method are co-equals which complement each other. Together they harmonize to form a complete methodology for delivering high quality products to our customers that meet or exceed their expectations. Neither can stand on its own to deliver high value to the business. They each have different roles in support of business initiatives. Throughout the life cycle both of these methods work together to achieve business goals, drive the value equation and progress organizational maturity. Though their activities differ greatly, they interrelate and harmonize to produce superior results.

A project management method provides detailed instructions for the discipline of planning, organizing, controlling, reporting and managing project resources to successfully complete project goals and objectives. It includes all of the activities for managing a project. A project is temporal in nature. It has a defined beginning and end. The project management method begins with project inception and closes when its product is delivered. When a project is over, the project manager moves onto something new.

The SDLC provides a framework that describes the activities performed during each phase of a systems development project. The SDLC is about quality, consistency and product delivery. It is about the realization of a product’s requirements. Products are of a more permanent nature than a project because products continue to exist long after the project that delivered it has closed. Therefore, the SDLC’s framework provides guidelines for supporting the product post production. Guidelines include practices for knowledge transfer, training, document turnover, maintenance and on-going support. When a product is to be retired, the project management method takes over to sunset the system. It is a full circle in a system’s life.

Project management is often expressed in terms of the constraints of scope, time and cost. This is also known as the project management triangle. Each side of the triangle represents a constraint. No side can be changed without affecting the others. At one time, “quality” or “performance” was considered a component of scope. The model has since been refined to delineate quality as a fourth constraint.

Time is the period available to complete a project. Cost is the project’s budget. Scope is what must be done to complete the project’s deliverables. The three constraints often compete with each other: scope creep means increased time and higher cost, a tight time frame may mean higher costs and less scope, and a tight budget may mean less time and reduced scope. Quality may be at risk if there are changes to any of the constraints.

To demonstrate the complementary nature of the SDLC to project management, I’ve contrived the SDLC triangle. Earlier I said the SDLC is about quality, consistency and product delivery. Quality, consistency and product delivery are the outputs of a defined, managed, measurable, repeatable and reusable set of processes and practices. The processes and practices form the core framework of the SDLC. Where a project is defined by its constraints, the SDLC is defined by its freedoms and empowerment. The SDLC empowers a project team to choose from among several approved pathways to deliver the highest quality products possible in the shortest amount of time and at the lowest possible cost.

Scope is a constraint that SDLC processes liberate by managing scope creep. Scope creep is a project killer. Let’s be clear, project scope will change during the course of a project. That’s because business priorities are fluid and may drive changes in projects so that evolving current needs are met. It’s how we manage scope that’s important. We’ll never be able to eliminate scope creep, but we can manage it effectively so it doesn’t become the constraint that kills our project. In many ways, managing scope creep begins with the project’s business analyst.

Consistency of process helps keep the cost constraint under control by practicing repeatable, measurable and defined algorithms. Let’s be pragmatic. Whenever we practice something, we get good at it. It doesn’t matter if we’re talking about music and the arts or sports or anything else. The old adage is “Practice makes perfect.” If we do something the same way over and over again, not only will we get good at it; we’ll find ways to improve what we are doing so we can do it faster, better and cheaper.

The schedule constraint is complemented by the SDLC’s timely delivery of a quality product that meets or exceeds customers’ expectations. If we manage scope creep effectively and are consistent in our ability to repeat and improve our processes, not only will we deliver a product on time, there may even be enough wiggle room in the schedule to address lower priority items or deliver the product ahead of the due date.

The complementary relationship between the SDLC and a project management method cannot be denied. They do not compete against each other.