Final Design Overview - A Crossrail Design Assurance Process

Assurance is defined as all the systematic actions necessary to provide confidence that the target deliverables have been met.

Assuring the Crossrail design proved extremely challenging due to the complexity and scale of the system and, with the designs being delivered via a significant number of different contracts, demonstration of a complete and fully integrated design was key.

The task of integrating the designs for the numerous aspects of the project - stations, shafts, portals and the various systems which makes up the end-to-end railway, and the task to demonstrate the collective designs are safe, operable, maintainable and perform (the Crossrail ‘4 Pillars of Assurance’) and meet the agreed requirements cannot be overstated.

In order to demonstrate this design integration and to test the designs against the 4 Pillars of Assurance, Crossrail, in collaboration with the Infrastructure Managers, developed the Final Design Overview (FDO) process.

The implementation of the process consisted of the following key steps:

• A series of FDO reviews covering all Crossrail Central Operating Section assets over a period of 8 months;

• Review and approval of an agreed list of key assurance deliverables for each asset and for the Programme (a total of 1000+ items of evidence);

• Collation and close out of an agreed list of outstanding issues (2000+) categorised to identify those critical for completion and sign off of each FDO;

• Signed FDO Certification covering all assets;

• FDO Reports covering all assets and a Programme FDO that are agreed with the IM and that baseline the FDO Design.

This Technical Paper will set out the details of the Final Design Overview Process and will describe the solutions employed to resolve some of the key challenges faced during its implementation.