"It might be a good idea to add this feature."
"Let's extend the test cycle so we have more data."
"I hate adding to your work but can you...?"

These sentences, once uttered, herald the onset of every project manager's recurring nightmare —  that phenomenon of a project ballooning in size and scope, while budgets and timelines remain the same. It's called scope creep. And it's deadly.

But what is it exactly, and how does it get past our defenses to slowly but surely inflate a project's scope?

The Definition of Scope Creep

In its simplest form, a project's scope is all about parameters. A project's scope should be a documented set of project boundaries, schedules, and major deliverables. These can be outlined in a statement of work.

Scope creep (also known as "requirement creep" and "feature creep") has become such a dirty word in project management because it refers to how a project's requirements tend to grow uncontrollably — often dictated by project stakeholders, or internal miscommunication, causing a Frankenstein-like mashup of features that weren't there during the planning stage. And often kill your deadlines. People often confuse scope creep and gold plating. The difference between scope creep and gold plating is that gold plating does not necessarily mean the project's requirements have changed, but that the project team has been working past the point of diminishing returns.

How Does it Creep Up on Projects?

Let's count the ways:

1. Lack of Details

The easiest and simplest culprit to blame for scope creep is vagueness. When there is a lack of a clearly-defined and controlled project scope (you can use a scope document template to create this), the scope will mutate. Don't be surprised if stakeholders and even team members choose to define your project more loosely than you envision. It's because you, as the project manager, didn't communicate the vision and the scope clearly enough in your Project Initiation Document!

TIP: The Project Scope Statement that goes into the Project Initiation Document is where you should lay out all project boundaries. Don't gloss over it. Spend time concretizing it so that expectations are managed, there are no surprises, and your stakeholders comprehend exactly what they'll get at the end of the process.

2. Weak Leadership

Here's the rub: stakeholders and clients may try to change the scope to get what they want if they sense that you lack experience, or are not a strong project manager.

TIP: This is based on their perception of you. Stand your ground if demands are beginning to inflate project scope. Communicate strongly through body language during meetings. And if your meetings are virtual, keep these virtual communication tips in mind.

3. Differing Stakeholder Opinions

Another possibility: you may have too many stakeholders, each with differing opinions. Too many cooks spoil the broth, as the adage goes. While stakeholders may all want the same end product, their motivations may vary wildly. And those motivations will affect what they feel should be prioritized during project development, which can wildly alter your timelines.

TIP: Limit the number of your stakeholders. Or try to determine their motivations so you can arrive at a common ground. If it makes sense, additional requests from stakeholders can be parlayed into a future project after the current one is done.

4. 11th Hour User Feedback

If you don't involve your end-users or your customers from the beginning of the process, introducing them midway through (or near the end of) a project, guess what happens? They may give you feedback you've never heard before, which often adds to your list of action items. Instant scope creep. Take the costly mistakes of the Denver International Airport project as a fair warning not to involve people late in the game.

TIP: The word you need to use here is collaboration. If you collaborate with your customers early and often, you run less risk of delivering something they don't need or want. Keep communication lines open so the ideas and the feedback keep flowing.

What are other ways Scope Creep creeps up on you?

Your turn. What other sources of scope creep did we miss? Add your thoughts in the comments and tell us how you've fought against the scope creep terror.

Read next: Lessons Learned in Scope Creep and Project Failure from Denver International Airport

Photo credit: Ana Julaton by Mark Sebastian