Better Business Cases (BBC) is a systematic way to prepare business cases for programmes or projects.
BBC is structured around the proven Five Case Model. The Five Case Model provides a disciplined, step by step approach that helps to ensure that each of the key aspects of a robust investment proposal is explicitly and systematically addressed as part of the business case development process. The five cases are addressed within the business case development process:

BBC was designed to help mitigate the common reasons why programmes and projects fail being: lack of strategic fit, lack of senior management engagement, lack of stakeholder engagement, focus first on funding then value-for-money, lack of supply side engagement; and lack of a systematic approach to considering investment proposals.
We recommended that senior management engage the key stakeholders (ie, those that are either highly influential in the investment decision and/or highly impacted by the change) to ensure strong strategic fit.
BBC is an iterative development process comprising a number of phases. The level of detail and completeness of each of the five cases are built up at different rates during the process using ten steps.

Each phase supports a key decision point.

Note: the Investment funding line above does not indicate a recommended approach; rather, it signals what new funding could be sought from the Crown at each phase of BBC development. If new Crown funding is needed, it must be sought supported by a business case that meets the Treasury’s guidelines. In the budget context that means a business case that meets the requirements of either a Detailed Business Case (DBC) or a Single Stage Business Case (SSBC), as appropriate and agreed with Treasury.
If the agency doesn’t have an appropriate business case ready, it can still proceed to bid if it has a letter from its minister supporting the agency doing so. Agencies should expect that Treasury will advise that if a proposal doesn’t meet the standard of DBC or SSBC, it should not attract an appropriation decision but could attract a contingency. In those cases the matter would need to come back to Cabinet for an appropriation decision.