Offshore Industry Pack

Offshore Cost & Schedule Forecasting

Offshore, the vessel is the clock. Cost accrues per day whether you are working or waiting on weather, which makes the weather-window distribution the single most important input to any credible forecast.

How the engine works
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Typical project-controls challenges in offshore

The method is the same everywhere. These are the sector conditions that make a generic approach wrong, and what each one means for how you control the project.

Vessel day-rates accrue regardless of progress

An installation vessel costs the same whether it is installing or riding out a swell. Cost is driven by days on charter, not by work completed.

Waiting on weather is full-rate cost

Weather windows are probabilistic

Operability depends on significant wave height limits against seasonal metocean data. A deterministic programme assuming average conditions will be wrong in one direction or the other, every time.

This is the definitive P50/P80 problem

Mob and demob are lumpy and non-recoverable

Mobilisation costs land in single large hits. A campaign split by an unplanned demob can absorb the entire contingency in one event.

One extra demob can exceed contingency

Spread cost compounds every delay

A delay does not cost one vessel. It costs the whole spread: installation vessel, support craft, crew transfer, ROV. Every day multiplies across the fleet.

Multiply daily burn by the whole spread

Campaign sequencing has hard seasonal limits

Miss the weather season and the remaining scope moves a year, not a month. There is no compressing your way out of a winter.

A slipped season is a slipped year

Which capabilities apply

Every tool below is a separate workbook that works on its own. These are the ones offshore teams tend to reach for, and what each one answers.

Analyse

  • Whether the programme you were sent is built properly, before you rely on it
  • Where the critical path really runs, and how much float is protecting it
Schedule Quality Analyser

Control

  • Cost and schedule performance against the baseline, in CPI and SPI
  • Change and risk exposure on one register, not in email
The core suite

Forecast

  • Outturn cost and completion date as a range, not a single number
  • The contingency needed to be 80% confident, not 50%
Forecast Engine

Measure

  • Progress claimed against rules of credit rather than opinion
  • An update block you can paste straight back into P6
Progress Measurement System

Contract & claims

  • Whether a submitted programme meets NEC4 clause 31.2
  • Productivity loss measured against an unimpacted period
NEC4 Compliance Disruption & Productivity Loss

Sustainability

  • Capital carbon baseline and forecast against target
  • Evidence trail for PAS 2080 assurance
Carbon & PAS 2080

How it runs, month to month

  1. Export two tables from P6 or Microsoft Project. An activity list and a relationship list. Nothing in your scheduling tool changes.
  2. Paste them in. The shaded cells are the only inputs. Everything else is formula-driven.
  3. Check the programme is sound. The schedule quality scorecard runs the DCMA checks and tells you what to fix before you forecast from it.
  4. Enter the period progress and cost. Earned value, actual cost and planned value by period.
  5. Read the forecast and issue the report. CPI, SPI, EAC and the P50 to P80 range, with the assumptions recorded alongside them.

What's in the Offshore edition

The engine is identical across industries. The edition supplies the content that makes it speak your sector's language, so it is useful the first time you open it rather than after a fortnight of setup.

WBS skeleton

  • Fabrication & load-out
  • Foundation installation
  • Cable lay & pull-in
  • Topside / turbine installation
  • Hook-up & commissioning
  • Demobilisation

Cost codes

  • Vessel day-rates by class
  • Spread support craft
  • Mob / demob lump sums
  • Fuel & consumables
  • Offshore crew & rotation

Risk register

  • Weather downtime beyond P50
  • Vessel breakdown
  • Cable damage during pull-in
  • Seabed conditions differ
  • Port or fabrication delay

Campaign milestones

  • Weather season open / close
  • Vessel charter start
  • First foundation installed
  • Cable energisation
  • Demob and handback

Worked example

Offshore wind foundations, 22 of 60 installed

BAC £184M. EV £61M, AC £73M, PV £67M. Weather downtime is running at 34% against a 26% baseline assumption, with 9 weeks of the season remaining.

CPI
0.84
Daily spread burn
£410K
P50 completion
Week 11
P80 completion
Next season
At P80 the campaign does not finish this season. That is not an 11-week overrun. It is a demob, a winter, a remob and a year of deferred generation revenue. The decision to add a second vessel has to be made now, not in week 9.

Illustrative figures, shown to demonstrate the method. Your numbers replace them.

Reports and outputs

Each of these is a sheet in the workbook. They recalculate when you enter the period progress, so there is nothing to assemble at month end.

Cost forecast

  • Three EAC methods side by side
  • CPI, SPI, cost and schedule variance
  • Variance at completion and TCPI

Monte Carlo

  • 1,000 iterations, no macros
  • P50, P80 and P90 outturn cost
  • Forecast duration and delay against baseline

Earned Schedule

  • Time-based schedule performance
  • Forecast completion date
  • Stays honest late in the job, unlike SPI

Cash flow and resources

  • Payment lag and retention modelled
  • Peak funding requirement
  • Resource forecast by period

Productivity

  • Trend against planned rate
  • Early warning before CPI moves

Assumptions and audit

  • Every distribution, its source and date
  • The record that defends the number

Offshore questions

You supply the metocean statistics for your site and Hs limits per operation. The pack provides the structure, not the hindcast data.
Yes. Compare scenarios on cost and completion probability, which is exactly the trade-off that decision needs.
Campaigns are modelled as discrete windows with their own operability, mob and demob costs.
Yes. The cost structure is the same, vessels, spread, weather. Only the WBS and installation units change.

Other industry editions

NuclearMulti-decade, regulator-gated ConstructionNEC4 valuation cycles Data CentresCost per MW, long-leads AirportsNight possessions, live ops OffshoreVessel rates, weather windows RailPossessions, GRIP/PACE stages Power T&DOutages, connections, consents Energy GenerationEscalation, grid dependency

Forecast offshore with numbers you can defend

Offshore Edition £349, all eight editions £999, complete suite £1,399