2 The PPP Contract included some clear and well understood obligations. The major contract management responsibilities that the parties needed to assume were explicitly stated, and deliverables under the contract were clearly established.
3 Ambiguity in parts of the Contract, however, led to disagreements between the contractual parties. Appendices 14 and 15 of Schedule 2.1 of the PPP Contract detailed the nature and extent of the works to be carried out - these differed for a station refurbishment, enhanced refurbishment and modernisation. However, ambiguous specifications, including phrases such as "replace/renew", meant that there was room for differing interpretations of what, for example, a refurbishment would entail. As a result, for works relating to the March 2005 and March 2006 station deliveries, scope had to be agreed for each station on an individual basis.
4 The minimal specification also led to diverging expectations between London Underground and the companies. While Metronet and Tube Lines tended to favour a less costly interpretation of the Contract, London Underground would often apply a more extensive interpretation. As a result, every station we examined was subject to extended scope disagreements, which in some cases was a key factor in delaying the progress of works.