The purpose of the Business Case theme is to establish mechanisms to judge whether the project is (and remains) desirable, viable and achievable as a means to support decision making in its (continued) investment.
It is a PRINCE2® principle that a project must have continued business justification.
The business justification is the reason for the project.
Without it no project should start.
If business justification is valid at the start of a project, but disappears once it is under way, the project should be stopped or changed.
In PRINCE2, the business justification is documented in a Business Case describing the reasons for the project based on estimated costs, risks and the expected benefits.
The reasons for undertaking the project must drive decision making.
When projects face changes or risks, the impact analysis should focus on the Business Case, remembering that the project is only a means to an end and not the end itself.
The ongoing and ever-present decision regarding the Business Case is whether the project can (still) be justified.
This is based on whether the project is desirable (the cost/benefit/risk balance), viable (the project can deliver the products) and achievable (the products can provide the benefits).
The Senior User(s) is responsible for specifying the benefits and subsequently realizing the benefits through the use of the products provided by the project.
The Executive is responsible for ensuring that those benefits specified by the Senior User(s) represent value for money, are aligned to corporate objectives, and are capable of being realized.
In PRINCE2, the Business Case is developed at the beginning of the project and maintained throughout the life of the project, being formally verified by the Project Board at each key decision point, such as end stage assessments, and the benefits are confirmed as they start to accrue.
In some cases the project may be initiated with a pre-existing Business Case (from corporate or programme management), in which case it will be refined during initiation.
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