Can the Engineer direct a Variation that modifies the order or timing of the Work's execution?

1. Role of Sub-Clause 13.1 [Right to Vary]

Sub-Clause 13.1 explicitly lists several forms of Variations that the Engineer may instruct, including changes to the sequence or timing of the execution of the Works (item (vi)). This clause grants the Engineer the authority to direct such changes, which might suggest an apparent right to influence the sequence and timing.

However, the FIDIC framework emphasizes collaboration and balance between the Contractor's autonomy and the Engineer's oversight. Any instructed Variation under Sub-Clause 13.1 must follow the procedures in Sub-Clause 13.3 [Variation Procedure], ensuring that it aligns with broader contractual provisions, including those related to the Contractor’s responsibilities.

2. Limitations on the Engineer's Right to Vary

While Sub-Clause 13.1 grants the Engineer the right to vary the sequence or timing of works, it does not automatically override other contractual obligations, particularly the Contractor's responsibilities for construction methods and planning under Sub-Clause 4.1 [Contractor’s General Obligations]. This clause states that the Contractor is:

“…responsible for the adequacy, stability and safety of all the Contractor’s operations and activities, of all methods of construction…”

Thus, the sequence and timing, as integral parts of the Contractor's methodology, are the Contractor's responsibility. Any unilateral variation by the Engineer that undermines the Contractor’s planning or construction methods could conflict with Sub-Clause 4.1. The FIDIC drafters likely intended the Contractor to retain primary control over construction means and methods to maintain accountability for their performance and safety.

3. Programme (Sub-Clause 8.3)

Sub-Clause 8.3 reinforces the Contractor's responsibility by requiring the programme to detail the order and timing of works. This provision demonstrates that the sequence and timing are central to the Contractor’s planning and execution strategy, which are subject to review but not direct control by the Engineer. The Contractor must submit the programme for approval, but approval does not transfer responsibility to the Engineer.

4. Purpose of Item (vi) in Sub-Clause 13.1

The inclusion of item (vi)—changes to the sequence or timing of execution—is not an unfettered right for the Engineer to alter the Contractor’s planned methodology arbitrarily. Instead, its purpose is to allow flexibility for circumstances where such changes become necessary due to external factors, including:

• Unforeseen conditions: New information or site conditions that necessitate adjustments in work sequence.
• Coordination with other contractors or Employer activities: Integration with Employer or third-party operations.
• Design or specification changes: Changes initiated by the Employer or Engineer that have downstream effects on timing or sequence.

In these scenarios, variations to sequence or timing must be communicated as part of the formal Variation Procedure under Sub-Clause 13.3, ensuring the Contractor has the opportunity to assess the impact and claim time and/or cost adjustments if justified.

5. The Engineer’s Boundaries in Using Item (vi)

The Engineer's ability to instruct a Variation under Sub-Clause 13.3 is not absolute. The Contractor can object if the instruction:

• Is unforeseeable based on the original scope (Sub-Clause 13.3(b)).
• Adversely affects health, safety, or environmental compliance (Sub-Clause 4.8, 4.18).
• Is impracticable due to resource availability.

Such limitations underscore that the Engineer's authority to instruct changes to sequence or timing is contingent on ensuring fairness and maintaining the Contractor’s central responsibility for the methodology.

Conclusion: Can the Engineer Instruct a Variation Affecting Timing or Sequence?

Yes, but with limitations. The Engineer can instruct changes to the sequence or timing under item (vi) of Sub-Clause 13.1. However:

The instruction must follow the formal Variation Procedure under Sub-Clause 13.3.        

It cannot compromise the Contractor's responsibility under Sub-Clause 4.1 or 8.3, unless explicitly agreed or justified by external factors.        

Such changes should aim to address unforeseen conditions or necessary coordination, rather than impose arbitrary control over the Contractor's methods.        

Practical Implication

In practice, the Engineer must use item (vi) sparingly and judiciously.