In most projects, a delayed task costs time that can be recovered later. In a shutdown, a lost shift on the critical path is lost production, and recovery options shrink every day the plant stays down. Shutdown schedule controls for critical path work exist to spot slippage within hours, not days, and to decide quickly what to do about it. The control cycle, progress measurement and recovery decisions are set out below for shutdown managers, planners and area coordinators.
What are shutdown schedule controls?
Shutdown schedule controls are the processes used to monitor progress against the shutdown schedule, update it shift by shift, identify threats to the critical path and make recovery decisions before the end date is lost.
Why shutdown schedules need tighter control
In a shutdown, the time available to recover from a delay shrinks every shift. A slip that a construction project might absorb over weeks can push the restart date within days, so control has to work in hours.
A schedule fit for control
Control starts with the schedule itself:
- Hour-level detail for critical work. Critical and near-critical jobs need steps measured in hours, such as opening, cleaning, inspection, repair and box-up.
- Correct logic. Dependencies between jobs, such as scaffold before insulation removal before inspection, must be in the schedule, not in people’s heads.
- Resource loading. Cranes, specialist crews and inspectors shared across jobs need to be visible, because they create hidden critical paths.
- Several critical paths. Large shutdowns often have more than one: a heater, a column and a reactor may each be close to critical.
The schedule is built from the frozen scope described in shutdown scope development.
The shift-by-shift control cycle
- End of shift: supervisors report job-step progress, problems and needs for the next shift.
- Schedule update: planners update progress and re-run the schedule, usually overnight for the day shift and during the day for nights.
- Morning meeting: area coordinators review the critical path, emergent work and constraints for the next 24 to 48 hours.
- Actions: resources moved, permits prioritized, decisions recorded in a decision log.
The cycle only works if progress reports are honest and timely. A job reported as 80 percent complete for three shifts running is a warning sign, not a status.
Measuring progress in a shutdown
Progress is best measured by completed job steps with agreed weights. As an illustration, an exchanger job might be weighted as follows; real weights should come from the work pack.
| Job step | Example weight |
|---|---|
| Isolate and open | 15% |
| Bundle pulled and cleaned | 30% |
| Inspected and repaired | 25% |
| Bundle reinstalled and boxed up | 20% |
| Tested and handed back | 10% |
Step-based measurement avoids the optimistic “percent complete” guesses that hide slippage. The principles behind weighted progress are explained more fully in construction progress measurement for project teams.
Managing emergent and discovery work
New work appears when equipment is opened. Each item should be assessed quickly: is it needed now, what will it take, and does it touch the critical path? Approved work is scheduled and resourced; deferred work is recorded for the next opportunity. Without this discipline, emergent work quietly absorbs crews planned for critical jobs.
Schedule recovery options
| Option | When it helps | Trade-off |
|---|---|---|
| Add shifts or crews to critical jobs | Work fronts allow more people | Congestion, fatigue, supervision demand |
| Resequence jobs | Logic has some flexibility | May move the bottleneck elsewhere |
| Run activities in parallel | Access and safety allow it | Higher simultaneous-operation risk |
| Defer opportunity scope | Low-priority work is competing for resources | Work waits for the next stop |
| Change the method | A faster technique exists | Requires approval and possibly new materials |
Indicators worth watching
- Float on the critical and near-critical paths, shift by shift
- Planned versus actual percent complete
- Earned versus planned hours
- Emergent work hours added each day
- Permit waiting time
- Jobs waiting on materials or inspection
Crew-level factors behind slow progress, such as access and materials, are covered in managing productivity during a plant turnaround. The wider planning effort is described in industrial shutdown planning services.
Apex Core Engineering provides planners and schedule control support for shutdowns through its project support services.
Frequently asked questions
How often should a shutdown schedule be updated?
At least once per shift for critical work, with a full update every day.
Why can a shutdown have more than one critical path?
Because several large jobs, such as a heater, a column and a reactor, can each take close to the full shutdown duration.
What is the most reliable way to measure shutdown progress?
Completed job steps with agreed weights from the work pack, rather than subjective percent-complete estimates.
Talk to Apex Core Engineering about shutdown planning and control support.