5 Common Causes of Shutdown Extension and How to Engineer Them Out

Look, we both know Shutdowns RARELY overrun for mysterious reasons. In most cases, the causes are predictable well before the mechanical window opens - if you know where to look. After enough Shutdowns and subsequent lessons-learned sessions, a large portion of the same issues continue to show up, and nearly all of them can be engineered out long before execution starts. Here’s what they are, and how to get ahead of each one.

‍

1. S.D.O.N.O (Scope Discovered Offshore, Not Onshore)

‍
We're working on our acronyms.

‍

The single most expensive way to plan a shutdown is to find out the true condition of a system once you're already in the window, with the clock running and a full spread mobilised. Late discovery forces rushed decisions, reactive procurement and rework, all on the critical path.

Engineer it out: invest in early offshore survey and accurate as-built data during the DEFINE and planning phases. Moving discovery onshore, where there's time to assess options and price them properly, is almost ALWAYS cheaper than discovering the same thing offshore mid-execution.

‍

2. Work That Could Have Happened

Pre-Shutdown, Happening in the Window

‍
Every task completed before the shutdown is critical-path time handed back to you. Too many programmes carry work into the window that never needed to be there - containment, cabling runs, temporary power arrangements, non-intrusive installations.

Engineer it out: build a deliberate pre-Shutdown work strategy that pulls everything possible forward. The goal is to arrive at the shutdown having already done everything that didn't strictly require an outage, so the window is spent only on what truly needs it.

‍

3. Assuming Everything Needs Replacing

‍
Blanket replacement can feel like the safe, thorough option. But, in practice, it often buys intrusive work, extended outages and cost that the actual condition of the equipment never justified - particularly on ageing assets where access is confined.

Engineer it out: verify what's actually defective before committing to wholesale replacement. A condition-led approach - retain what's proven serviceable, replace only what testing shows is failed, and hold a compliant fallback where needed - can take significant intrusive scope off the critical path.

‍

4. Isolation and Access Planned Too Late 

‍
The job a drawing says will take twenty minutes routinely takes three days offshore - because the access wasn’t walked, the isolation wasn’t confirmed, or what surrounds the worksite wasn’t accounted for. Access and isolation are where optimistic plans meet unforgiving reality.

Engineer it out: plan isolation and access early, and validate it physically rather than on paper. Walking the job before the window turns unknowns into knowns while there's still time to do something about them.

‍

5. No Fallback When Reality Bites

‍

Every shutdown throws up something unexpected. A plan with no contingency turns a small surprise into acritical-path delay, because there's no pre-agreed route forward and decisions get made reactively under pressure.

Engineer it out: build the fallback strategy in before you need it. Knowing in advance what you'll do if a component fails verification, or a scope grows, keeps a surprise from becoming an overrun.

‍

The Common Denominator

‍
None of these causes are exotic. They're the predictable, repeatable elements that separate a shutdown shaped by assumptions from one shaped by evidence. Getting ahead of them is what turns a shutdown from a schedule risk into a controlled, planned event.

We applied exactly this thinking on a live FPSO electrical upgrade - challenging the assumption that all components needed replacing, and using early survey and pre-TAR works to cut shutdown exposure - which you can read more on here: https://www.katoni.com/inside-katoni/how-early-constructability-thinking-reduced-shutdown-risk-on-a-live-fpso-electrical-upgrade

Planning a shutdown scope? Get in touch - we'd welcome the conversation ;)‍