Completion should be judged against the purpose of the bargain, not merely the number of open defects.
The Week 5 materials begin with a strict proposition: some contracts require entire performance. The classic example is Cutter v Powell, where payment depended on completion of the whole voyage. The sources then recognise that rigid application can produce harsh results and introduce exceptions, especially substantial performance.
For project leaders, this maps directly onto acceptance, commissioning and handover.
The Strategic Context
Projects rarely reach physical perfection at the exact moment of contractual completion.
A plant may operate but have minor documentation defects. A fit-out may be usable while requiring cosmetic rectification. Software may meet its functional purpose but still have low-severity bugs.
The Week 5 material contrasts Hoenig v Isaacs and Bolton v Mahadeva. In the first, relatively minor defects did not prevent substantial performance. In the second, defects in a heating installation were sufficiently serious that the principal objective had not been achieved.
That distinction is commercially valuable.
What Leaders Commonly Misread
The first mistake is treating any defect as proof that the contractor has not performed.
The second is the opposite: treating any usable output as substantially complete.
The source focuses on whether the principal objective of the contract has been achieved.
The third is using cost of rectification alone as the test. Cost can be evidence, but the functional significance of the defect matters.
The fourth is failing to distinguish completion from final perfection. A project may be sufficiently complete to trigger payment while still leaving the innocent party with a set-off or damages claim for defects.
Current Australian treatment of entire obligations, substantial performance and set-off should be verified before publication of definitive legal rules. [FACT CHECK REQUIRED]
Reframing the Issue
The project question should be:
Has the supplier delivered the outcome the contract was fundamentally intended to create?
That requires an outcome hierarchy.
Not every defect should carry equal weight.
A missing operating manual may be important but not equivalent to a safety-critical defect that prevents commissioning. A cosmetic defect is not equivalent to a heating system that does not heat.
Strategic Analysis: Defects Through an Enterprise Lens
The Week 5 tutorial applies this directly to the Fratelli refurbishment scenario. James and Mary are unhappy with workmanship, but the answer guide distinguishes minor defects from defects so serious that the refurbishment's principal objective is not achieved.
This is a useful model for modern project governance.
Hypothetical manufacturing example: A new automated line meets output, safety and quality requirements but has several non-critical labelling defects and incomplete spare-parts documentation. The project may reasonably distinguish those issues from a situation where the line cannot achieve the required throughput or cannot be operated safely.
The commercial question is then not “are there defects?” but “what level of defect prevents completion?”
That threshold should be designed before delivery, not invented at handover.
Decision Framework
Classify defects against four criteria.
Functional impact
Does the defect prevent the asset or service from performing its intended purpose?
Safety or regulatory impact
Does the defect make operation unsafe or unlawful?
Economic impact
Does the defect materially erode the value of what was purchased?
Rectifiability
Can the defect be corrected without fundamentally rebuilding the deliverable?
This produces a more disciplined completion decision.
From Strategy to Execution
Immediate action: define completion criteria in measurable terms before work begins.
Medium-term capability building: create a defect-severity model aligned with contractual payment and acceptance. Critical, major and minor defects should have different consequences.
Long-term strategic positioning: link completion criteria to the business case. The project should not be declared successful because contractual paperwork says “complete” if the enterprise outcome remains unusable.
Portfolio Governance Implication
Substantial-performance disputes should also be reviewed for recurrence across the portfolio. If the same supplier repeatedly reaches “completion” with material defects, the issue is no longer only the payment position on one contract. It may indicate weak acceptance criteria, supplier capability problems or a procurement model that rewards nominal completion over operational readiness.
Portfolio reporting should therefore distinguish commercial completion from operational readiness. A contract may reach a payment milestone while the business still carries rectification, training or performance risk. Making that distinction visible helps executives avoid declaring value realised before the asset or service is genuinely dependable.
Signals to Monitor
Watch for project teams holding final payment over minor defects unrelated to core performance, contractors claiming completion despite unresolved critical failures, acceptance criteria being created after disputes arise, and defect lists that make no distinction between cosmetic and outcome-critical issues.
Questions for the Leadership Team
- What is the principal objective of each major contract?
- Which defects make that objective unachievable?
- Are completion criteria measurable and agreed before handover?
- Does payment architecture distinguish substantial completion from final rectification?
- Are safety and regulatory defects treated differently from cosmetic defects?
- Can leaders explain why a project is “complete” in outcome terms?
Closing Perspective
The strongest completion regime does not reward poor work and does not weaponise trivial defects.
It asks the harder question: has the bargain delivered its central purpose, and what remains to be corrected before value is fully realised?
Related article: Which Contract Terms Are Truly Critical? Designing Conditions, Warranties and Remedies Around Enterprise Risk
Related article: Contract Management Is More Than Contract Administration
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