The United Kingdom's Future Nuclear Deterrent Capability - Public Accounts Committee Contents

Supplementary memorandum from the Ministry of Defence

Question 62 (Mr Burstow):   An amount of overlap between project design and construction phases

  In answer to question 62, Guy Lester undertook to set out for the Committee the amount of overlap between project design and construction phases for the Astute, Type 45 and Nimrod projects. Before providing specific project information, it may be useful to explain why projects include overlap in their planning.

  For certain types of projects it is not necessary to complete all aspects of the design work prior to the start of construction. This is particularly true for maritime projects, where programmes comprise a number of elements, and the full design for some of these elements may be reserved for a later date, providing the interface has been specified. For example, it is possible to start construction of a submarine hull before the design of the command and control system is finalised. As well as reducing the time taken for the delivery of the capability, this approach allows emergent technology to be utilised and reduces the chances of equipment becoming obsolescent before it enters service. In contrast, for other types of equipment such as aircraft, where there is a greater degree of systems integration, there are fewer opportunities for design and construction work to overlap as a larger proportion of the design would normally need to be completed prior to the start of construction.

  It is part of the normal process of project management to identify dependencies between project elements, so that an efficient programme is developed that takes advantage of opportunities for activities to occur in parallel and for technology insertion during the manufacture phase.

  Details of the overlap for individual projects are below.


  The Type 45 project is not necessarily representative of all ship projects as much of the design work was completed under the earlier multinational Project HORIZON, with the Type 45 project inheriting a relatively mature design. The overlap for the project is as follows:

    Planned date for completion of main design phase: April 2003

    Actual date for completion of main design phase: January 2004

    Planned and Actual start of construction: March 2003

    Planned Overlap: 1 month

    Actual Overlap: 10 months


  It is not possible to provide a simple statement of the overlap between different phases. The original contract for Nimrod MRA4 in 1996 introduced some concurrency between the design and construction phases. This approach was unsuccessful, so in 2003 the contract was renegotiated to largely remove concurrency. In 2006 the design was judged to have reached sufficient maturity for full production to be re-commenced. Although design work was continuing and therefore some concurrency remained, this was assessed as being a low risk due to the maturity of the design at that point.


  The planned overlap between Design and Manufacture was three years. In practice, the actual overlap was as follows:

    Completion of detailed design phase: June 2003

    Start of construction: 2000

    Overlap: 3.5 years

5 December 2008

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