The project scope is finalized. You feel like throwing a celebration. It took more time than planned, but it seems like all of the stakeholders have agreed on what is really needed to meet project objectives. About five minutes after receiving final scope approval, your stakeholders began asking about more definitive estimates for schedule and budget.
Your stakeholders know the process. It is understood that you and the team will take the agreed-upon scope, create a work breakdown structure (WBS), and use this to fully define the work to be completed and to create better estimates. Because the scope definition went over schedule, and since your team members are busy, you realize that you can create the WBS. You realize that you know the project phases intimately. And before you became a project manager, you were involved in the hands-on details of the work. With these thoughts in mind, you decide that you will create the WBS.
STOP RIGHT THERE! This is a horrible idea. Seriously, one of your worst ideas. Your intentions are pure. But do not create the WBS without your team. It does not matter how much you think you know. Or how much you actually know. You have a team full of experts. They know more than you do about the work. That is how it is meant to be. You are an expert in project management.
Your team members will catch things that you will not. They will collectively come up with questions and resolutions that would never have occurred to you. You need multiple eyes and brains in this process. Every major area of scope requires representation. These are the people who will ask the right questions, such as, “How will our two systems interface?” Or “Who is taking care of functionality X?”
You are not helping your team by creating the WBS without them. Take the time, include the right people, and create the best WBS possible. That’s not too much to ask for something that is going to drive your schedule and budget and resource plan.