The development of the business case is a detailed extension of the work undertaken in the preliminary assessment stage. While the following steps are presented in a linear manner, the reality of their achievement is much less sequential and more iterative. The elements of the business case are developed iteratively to allow for ongoing review and assessment. Step-wise assessment ensures that the project retains its focus on the service requirements and that the chosen project delivery options are those most likely to deliver value for money. As a result of the iterative development of the business case many elements will be developed contemporaneously, with the information generated in one place required to inform and refine a number of other elements.