Five Signs a Project Has an Interface Problem
Interface failures rarely announce themselves. They tend to surface as smaller, unconnected issues until the cumulative effect becomes impossible to ignore.
Marcel Mbene, ChPP — Founder, Bold Leverage Ltd · 13 July 2026
An interface is any point where responsibility, information or physical works pass between two parties, disciplines or contracts. Every complex project has dozens of them. Most are managed without incident. The ones that are not tend to follow a recognisable pattern.
1. Design queries take longer to close than they should
When a technical query sits open for weeks rather than days, it is often not because the question is difficult — it is because no one is clearly accountable for the boundary the query sits on. Slow query resolution is frequently the first visible symptom of an interface that has not been properly assigned.
2. Two parties both assume the other owns a scope item
Gaps in scope are far more common at boundaries than within a single discipline's core work. If a scope item is discovered late because both sides believed it belonged to someone else, that is a strong signal the interface was never explicitly defined.
3. Programme float disappears at the same recurring point
When schedule slippage repeatedly clusters around the same handover point — design to construction, civils to services, one contractor's work to another's — the interface itself, not the individual parties, is usually the root cause.
4. Meetings discuss the same coordination issue without resolving it
A coordination item that reappears on a progress meeting agenda for several weeks running, without a clear owner or close-out date, indicates that the interface lacks an effective governance route — not that the issue is unusually complex.
5. Contractors raise early warnings or notices about each other's information
When one contractor is formally noting delay caused by late or incomplete information from another party, the underlying issue is very often an interface that was not adequately defined or resourced at the outset.
Our view
None of these signs, taken alone, is proof of a serious problem. Together, and left unaddressed, they are one of the most reliable early indicators of cost and programme overrun on complex projects. Interface management is a core part of our engineering consultancy and delivery assurance services, precisely because it is where so much avoidable risk originates.