The Contract is likely to define a class of events which allow the Contractor to claim relief from the contractual implications of any performance failure resulting from that event, including those set out in the Payment Mechanism. These are typically referred to as Excusing Causes. Relief is not given to the Contractor automatically - it has to be claimed by the Contractor within a specified time period.
The WIDP Contract (Clause 41) defines Excusing Causes as:
a) the closure of a facility that has been pre-agreed with the Authority;
b) the implementation of an Authority Change;
c) the implementation of a Qualifying Change in Law; and
d) the implementation of instructions from the Authority in the case of an Emergency (see Section 4.3.6).
The time limit for making a claim is thirty Business Days from the Contractor becoming aware of the Excusing Cause.
The Contract Management Manual should provide a clear reference to the section of the Contract where Excusing Causes are defined, or reproduce the Contractual definition in full. A simplified version of what can be a complex definition is not recommended in this case as it could be misinterpreted. The Contract Management Manual should also state the time limit for the Contractor to make a claim.