Both the specifications of the change itself, and correspondence and discussions with the private party in relation to the change, should be fully documented and kept in order to avoid subsequent disputes as to what was agreed. This is an aspect of appropriate communication planning and management (as detailed in Chapter 4).
It is vital that changes modifying a project deed are documented as formal amendments using an appropriate version control process. Any change negotiated between the parties should not be effective unless and until it is formally agreed. The parties should not rely on informal agreements for noncompliance with the terms of the project deed. However, occasionally a proposed amendment will impose no new or additional obligations on the government party, and will not relieve the private party of its existing obligations. In these circumstances, it may be appropriate for the parties to agree to treat the amendment as being effective before the formal documentation is executed.
As noted above, major change processes require a detailed implementation plan, which should be documented in advance of implementation.