A similar analysis has been undertaken using a more limited set of projects which are now relatively mature (more than 75% complete) and for which Initial Gate50 estimates are available.
For further detail on the sample and methodologies used to undertake the analyses presented in this section, please refer to Appendix F.
Table 7-6 sets out the results of the analysis of the mature projects for which Initial Gate50 estimates of duration and cost are available.
| Average cost | |
Estimate at Initial Gate50 | 38 | 1,141 |
Straight average increase on a project-by-project basis to Latest50 (75% mature) | +49% (19 months) | +33% (£377m) |
Sample size | 23 | 15 |
+81% | +42% |
Source: CMIS, Review team analysis
Table 7-6: Duration and cost of Assessment, Demonstration and Manufacture phases
The data in Table 7-6 appears to suggest that performance is moderately improved when considered for a consistent set of projects rather than as the composite of analyses based on Initial Gate and Main Gate estimates. However:
• the sample for this analysis is significantly smaller than the analysis compounding the Assessment phase and Demonstration and Manufacture phase dynamics; and
• this sample is unrepresentative of the broader portfolio of projects managed by DE&S due to an inherent sampling bias towards projects which are running to schedule, which are in turn also more likely to be running to budget.
Consequently the Review team believes that the compound analysis is the most robust approach given the data available.