3.4  Project time periods for analysis

To overcome the limitations of earlier studies that simply compared the budget to actual project outcomes it was decided to adopt four time periods between project milestones for assessment. These four time periods were used to measure, compute and compare the relative performance of PPPs and Traditional procurement, they were:

Original Announcement means the first time the project was publicly announced. Budget Approval means the point at which the relevant government approved the project budget prior to engaging the market.

Contractual Commitment is the time of contract execution and/or financial close. Actual Final is the commissioning time for the infrastructure.

These four periods are shown graphically in Figure 1.

Figure 1: Comparative periods of assessment (source: Duffield 2008)

Each of these periods provides insight into different aspects of the projects and the inclusion of all periods provides the opportunity for a balanced appraisal of PPPs versus Traditional projects taking into account the different project processes between the two approaches. The rationale of the different periods is provided below: