PRINCE2 Stage Gate Model

prince2 stage gate

PRINCE2 uses a Stage Gate model to control project progress.  This means we break the work to be delivered up into manageable sections.  PRINCE2 calls these sections; Management Stages. At the end of each section, or Stage, we do 3 important checks:
  • Look Back - to ensure the work of the current stage is done
  • Look at the Big Picture - review the viability of the project in the business case, check the schedule in the project plan and ensure that all risks are documented and under control
  • Look Forward - produce a Stage Plan to cover the work in the next, upcoming Stage.
As a Project Manager, a management stage is the work you have approval to complete from your Project Board.  It's the limits of your authority.   Along with the concept of Tolerance, the PRINCE2 Stage Gate approach supports the principles of Manage By Stages and Management by Exception.

The PRINCE2 Stage Gate - how do we get through?

At end the end of a Stage it's not automatic that the project proceeds.  You need to think of the Gate as closed and the project must produce enough good information to prise it open and justify continuation. In PRINCE2 this happens at an End Stage Assessment. This is where the Project Board get together to decide whether to carry on with the project or not.   The end stage assessment can be a formal meeting or, in smaller projects, could be done virtually or by phone / email. So what information are the Project Board looking for?  It's all down to the 3 important checks we identified at the start of this post:

Look Back

The Project Board will want to review the stage that has just completed.  Has the work they authorized at the last End Stage Assessment been completed, tested and accepted by the Customer?  An End Stage Report document is used to show how the stage has performed against targets for time, cost, quality, scope, risk and benefit.

Look at the Big Picture

The "Big Picture" in PRINCE2 is covered with an update to 3 management documents
  • Business Case - this is updated with project actuals.  Even if the overall justification for the project is not in doubt small, incremental, times and costs should be recorded and the business case updated.  Changes to the Business Case may affect forecast benefits, so the project Benefits Review Plan is also updated.
  • Project Plan - while the current stage may be finishing on time, the Project Board needs a view of the entire project.  The updated Project Plan provides a view on progress to date, combined with the forecast activities in the next and future stages
  • Risk Register - at the end of stage some Risks can be closed out, other ones may become more relevant as their proximity nears.  An update to the risk situation helps the Project Board gain a view of all the uncertainties the project faces.  And, with this information they can decide if the project remains within their level of Risk Tolerance

Look Forward

In addition to the past and current situations, the Board needs to see what is expected in the following stage and the resources required.  So a Next Stage Plan will set out the products to be developed, a detailed schedule for that stage and any risks involved So how do I as a Project Manager provide the Board with the information they need so they can make an informed decision to move to the next step in this Stage Gate approach?

PRINCE2 - Managing a Stage Boundary process

This process is all the work of the Project Manager and is all about us looking back, at the big picture and looking forward. During the process we will create a Stage Plan for the following stage. The Stage Plan sets out the work that will be carried out and is the work that we will be managing on a day to day basis. We will also update the Project Initiation Documentation – including the Project Plan and Business Case. This allows the Project Board to see where we are vs. where we hoped to be and also whether the justification is still there to continue with the project. Also, as part of this process we will create the End Stage Report to review the stage just finished and provide the Project Board with all the information that they require to move through the Stage Gate process.  The updated Project Initiation Documentation and End Stage Report are then used by the Project Board to review and decide if we will continue. If they say yes they open the next PRINCE2 Stage-Gate and let the Project Manager through but if they say no the project can be closed or, at least, paused to get things back on track. So the PRINCE2 Stage Gate model ensures that projects cannot progress further than the end of a stage (phase) before they are reviewed by senior management.  Project Managers know their boundaries, Project Boards (sponsors) don't need to micro-manage and the project progress is controlled at an appropriate level. It's not called PRojects IN Controlled Environments for nothing!