Step 1: Set the Direction
Start off by setting the direction for the project. Do you have an agreed Project Vision, Objectives and Timeframes? Are they specified in depth and has your customer agreed to them? Does everyone in the project team truly understand them and why they are important? Only by fixing the project direction can you truly fix the project scope.

Step 2: Scope Workshops
The best way to get buy-in to your project scope is to get all of the relevant stakeholders to help you define it. So get your project sponsor, customer and other stakeholders in a room and run a workshop to identify the scope. What you want from them is an agreed set of major deliverables to be produced by the project. You also want to know "what's out of scope".

Run the workshop by asking each stakeholder for a list of the deliverables they expect the project team to deliver. Take the full list of deliverables generated in the workshop and get them to agree on what's mandatory and what's optional. Then ask them to prioritize the list, so you know what has to be delivered first.

Step 3: Fleshing it out
You now have an agreed list of deliverables. But it's still not enough. You need to define each deliverable in depth. Work with the relevant people in your business to describe how each deliverable will look and feel, how it would operate and how it would be supported etc. Your goal here is to make it so specific that your customer cannot state later in the project that "when they said this, they really meant that".

Step 4: Assessing Feasibility
So you now have a detailed list and description of every deliverable to be produced by your project, in priority order and separated as mandatory / optional. Great! But is it feasible to achieve within the project end date? Before you confirm the scope, you need to review every deliverable in the list and get a general indication from your team as to whether they can all be completed before your project end date. If they can't, then which deliverables can you remove from the list to make your end date more achievable?

Step 5: Get the thumbs up
Present the prioritized set of deliverables to your Project Sponsor and ask them to approve the list as your project scope. Ask them to agree to the priorities, the deliverable descriptions and the items out of scope.

By getting formal sign-off, you're in a great position to be able to manage the project scope down the track. So when your Sponsor says to you in a few weeks time "Can you please add these deliverables to the list?", you can respond by saying "Yes, but I'll either have to remove some items from the list to do it, or extend the project end date. Which is it to be?". You can easily manage your Sponsors expectations with a detailed scope document at your side.

The scope document is the Project Manager's armor. It protects them from changes and makes them feel invincible!