A written instrument authorizing alterations to the original contract documents before complete agreement on adjustments to cost or schedule is reached. It directs the contractor to proceed with a modification to the work. For example, if unforeseen site conditions necessitate a different foundation design, this instruction allows work to continue without delay while the final cost impact is being negotiated.
This mechanism offers crucial flexibility in dynamic building projects. It mitigates delays that can arise from protracted negotiation over changes, keeping the project progressing towards completion. Historically, it emerged as a solution to address the inherent uncertainties and complexities common in large-scale developments, providing a structured approach to managing evolving requirements and unexpected issues.