Resource loading: when it's worth it, when it isn't

Four things, and they are worth naming individually because most projects need only two of them.

• A defensible manpower histogram. The most commonly required deliverable in the Gulf. A histogram drawn in Excel alongside the programme drifts from it within two updates. One generated from the schedule cannot.
• Proof that the plan is achievable. A duration built on a crew of 30 is only credible if the histogram shows 30 people available on that date and the site can hold them. Loading is what connects the two.
• The basis for a disruption argument. Planned man-hours against actual man-hours, by period and by area, is the raw material of nearly every disruption claim. Without a loaded baseline, the planned side of that comparison does not exist and cannot be created afterwards.
• Earned value. Only meaningful where the schedule and the cost model share the same breakdown structure, which is less common than it sounds.

The cost is not setup. It is every update, forever.

• Statusing doubles. Every update now requires actual units as well as actual dates, from a source that is usually a different department.
• Wrong assignments corrupt the histogram silently. Units per time entered at the wrong rate produces a peak nobody can explain, and it will be spotted by a reviewer before it is spotted internally.
• Cost in the schedule conflicts with cost in the commercial system. Two numbers for the same thing, diverging monthly, is a problem that reaches senior people quickly and never reflects well on the programme.
• Duration changes do not always recalculate units the way people expect. Depending on the duration type, changing a duration will change either the units or the units-per-time, and the one it changes is the one you were not thinking about.

Load labour only. No plant, no materials, no cost.

Create one resource per trade — steel fixer, carpenter, mason, electrician, pipe fitter — as labour resources with no cost rate attached. Assign them to construction activities at the crew sizes used in the duration build-up. Leave engineering, procurement and approval activities unloaded, or loaded only where a real team is committed.

This gets you the histogram, the achievability proof and the planned side of any future disruption comparison. It avoids the cost reconciliation problem entirely, because there is no cost in the file to reconcile. It roughly halves the statusing burden compared with a fully loaded programme.

It is also the arrangement most Gulf consultants actually want when they ask for resource loading. Confirm what the specification requires before building anything more elaborate.

Usually not, and if you do, keep a copy of the file from before you did.

Levelling changes dates according to resource availability rather than logic. Three consequences follow, and all three are difficult to manage on a live project.

The dates move for a reason that is not visible on the bar chart. An activity has slipped three weeks and no relationship explains it. Anyone reviewing the file — including you, in four months — cannot reconstruct why.

The critical path becomes resource-driven. The longest path no longer describes a chain of physical dependencies, so the critical path test behaves unpredictably and the driving path narrative becomes very hard to write.

And levelling results are sensitive to settings, priorities and availability curves that are rarely documented. Re-running the same file next month with the same data can produce different dates.

The alternative is to use the histogram diagnostically rather than mechanically. Load resources, look at the peaks, and fix the peaks by changing logic, splitting activities or re-sequencing areas — decisions a person makes and records. The dates then move for reasons that are visible in the file.

The last row is the one that matters most. A loaded programme that is not statused fails DCMA check 10 in spirit while passing it mechanically, and it produces an actuals histogram of zero against a planned peak of 400. That has been noticed at a monthly meeting more than once.

• Check 10 — resources. The Schedule Health Check reports this as informational rather than as a failure, because an unloaded schedule is a legitimate approach. What is not legitimate is not deciding. Write the approach into the schedule basis memorandum either way.