Development of Cost Estimate Plans — Process
Producing an estimate is itself a mini-project to be scoped, scheduled, and resourced — and for a process plant the plan is organized around engineering disciplines, not building trades. It's the process sibling of the building estimate plan: same planning discipline, structured by discipline and gated by PFDs, P&IDs, and the equipment list. Built on AACE 36R-08.
What it is — and how it relates to 35R-09
This is the direct counterpart to the building estimate plan (Lesson 16). The discipline of planning the estimate effort is the same; only the organizing structure differs — process estimates are coordinated across engineering disciplines rather than building trades, and gated by process deliverables rather than design phases.
What shapes a process estimate plan
- Discipline-based work split — Tasks divide by engineering discipline; the plan assigns each and defines the interfaces between them.
- Deliverable-gated method — Method per discipline depends on what's available — equipment-factored early (PFDs), detailed later (P&IDs and MTOs).
- Equipment list as the spine — The equipment list anchors the estimate; the plan sequences work around when it firms up.
- Bulk material take-offs — Piping, electrical, and instrumentation bulks need planned take-off effort once design matures.
What goes into a process estimate plan
| Element | Process-specific content |
|---|---|
| Scope & structure | Breakdown by discipline and by process area/unit |
| Tasks & interfaces | Discipline assignments and clear interface boundaries |
| Schedule | Sequenced around equipment-list and P&ID maturity |
| Data & methods | Equipment pricing sources, factors, bulk take-off methods |
| Tools | Process estimating software, equipment cost databases |
| Review & quality | Discipline checks plus an integrated cross-check |
Using the process estimate plan
For a process estimate, draft the plan from the agreed requirements (ERD): break the work down by discipline and process area, assign every interface, sequence around when the equipment list and P&IDs firm up, and protect discipline checks plus a final integrated cross-check. The result feeds cleanly into the process basis of estimate (next lesson), which documents what the plan produced.
Nine things to remember
- 36R-08 plans the estimate effort for process projects — the sibling of 35R-09.
- Same planning discipline, process structure — disciplines, not trades.
- Organized by engineering discipline — process, piping, instrumentation, civil, etc.
- Gated by deliverables — equipment-factored early, detailed take-off later.
- The equipment list is the spine — sequence the plan around it.
- Discipline coordination is the core challenge — define boundaries clearly.
- Interfaces are where scope leaks — assign every one explicitly.
- Plan discipline checks plus an integrated cross-check.
- The plan feeds the process BOE — which documents what it produced.
Glossary
- Bulks
- Piping, electrical, instrumentation materials.
- Engineering discipline
- Process, mechanical, piping, instrumentation, electrical, civil.
- Equipment list
- The spine deliverable anchoring the estimate.
- Estimate plan (process)
- The plan for producing a process-plant estimate.
- Integrated cross-check
- A review that the assembled multi-discipline estimate is consistent.
- Interface
- A boundary where two disciplines' scope meets.
- MTO (material take-off)
- Measured quantities of bulk materials.
- Process area / unit
- A section of the plant used to structure scope.