Employer's Requirements: scope boundaries, battery limits and interface matrices

Ambiguous scope boundaries are one of the most expensive tender-document defects. A package should identify physical battery limits, design boundaries, tie-in points, temporary interfaces, Employer-furnished items, utilities, access, enabling works and third-party responsibilities at a level that can be priced and scheduled.

An Interface Responsibility Matrix is particularly useful where civil, mechanical, electrical, automation and external utility packages meet. Each interface should identify design responsibility, supply responsibility, installation responsibility, testing responsibility, required information, predecessor activity and acceptance evidence.

Employer-furnished information and assets should be separated from contractor verification obligations. If the Employer provides surveys, utility records, geotechnical information or existing drawings, the tender should state what status that information has and what additional investigation the contractor must perform.

The interface matrix should be reconciled with the BOQ, drawings, technical specification and programme milestones before issue. A responsibility that exists only in one document is a future clarification or claim waiting to happen.