Scope creep is one of the many challenging things I experienced in my former life as a digital marketing account manager. This phenomenon occurs when you’ve already started a project and someone requests a change or a new direction that impacts your process, timeline, and costs.

Those who manage projects and constantly fall victim to scope creep don’t have the best reputation: whether it’s your fault or not, delivering a ballooning project six months late and $500K over budget just doesn’t look good. Thanks to my own years in the trenches and smart advice from other PMs, I’ve realized that controlling scope involves advance planning and meticulous documentation. Here are four steps to undertake.

Outline Your Purpose

When everyone agrees why you’re doing the project and what you’re expected to achieve, you prevent surprises later. Before you do anything else, share your objectives and anticipated results with your sponsor and stakeholders. Misunderstandings among various parties with different ideas about project outcomes causes scope creep, so now is the time to invite detailed feedback.

List Your Project Deliverables

Projects can’t be all things to all people, so plan carefully and prioritize your focus. Think about what output or functionality should be delivered when. Consider aspects like timeline, budget, development approach, quality assurance, and launch. List them in order from most critical to least critical and get sign-off from your stakeholders.

Create Your Workflow

Once you’ve nailed down your deliverables, assign specific work tasks and an appropriate team member to each. Using a relevant software program, develop a critical path of tasks and sub-tasks – noting when a task is dependent upon another’s completion. List project milestones, and in your timeline, leave room for the unanticipated setback. When in doubt, allot more time than you think you need.

Present the workflow to the higher-ups. Reiterate that if the development process strays from the plan or changes are requested once a task has been completed, you will face time and cost implications.

Insist On Change Forms

Familiarize stakeholders and team members with the change form, or document that clearly details a requested change and how the change impacts the timeline and project costs. The change form assesses whether it’s worth it to make a change or whether it should be tabled. Introduce it at the beginning of your process, and don’t consider a requested change without having one in hand.

Although some scope creep is inevitable, prevent it with systematic documentation throughout the project development process. Some additional work upfront pays off big time in the long run.