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

What breaks forecasts in offshore

The maths is the same everywhere. These are the sector-specific conditions that make a generic forecast wrong.

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

What's in the Offshore pack

The engine is identical across industries. The pack is the content that makes it speak your sector's language from the first time you open it.

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.

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 packs

Forecast offshore with numbers you can defend

Forecast Engine $299 · Offshore pack $99 · all eight packs $499