Resource loaded CPM scheduling pertains to developing schedules based on activity durations predicated on production rates and constraints of available personnel or resources. Many project specifications state a requirement for resource loading – and its cousin ‘cost loading,’ yet resource loaded schedules tend to be the exception. Despite that, the requirement seems to be routinely ignored and rarely enforced by stakeholders.

Schedulers often tend to  verify what the availability of resources will be for a given trade, or the flexibility they have to resequence or accelerate a project. If you don’t know what you need for Plan A – you can’t calculate for Plan B. Given the rate of projects that are disrupted or delayed, schedulers will be hard put to make accurate adjustments to resources if they have no baseline

There are specific reasons why resource loaded schedules are the exception in the building industry:

There is a dearth of experienced CPM operators in the industry who know how to make proper schedules – resource loaded or not. Those who can create them are but a tiny subset. A more realistic goal is to generate a coherent schedule that doesn’t use resource loading, but that is usually an unfulfilled ambition 

Scheduling platforms – such as Primavera 6 – offer a substandard interface for resource loading that makes it difficult to develop any semblance of veracity or certainty. Other platforms do have proper resource loading modules, but those have considerably less market-share than Primavera. These include MS Project, which has no reliable resource loading module, and for my money, is otherwise of little practical use in industrial planning. 

“The first instinct upon receiving an MS Project schedule – without even looking at it –  is to convert it to another platform – like Primavera 6. If you’re practical minded – and not a masochist –  you’ll just regenerate it from scratch.

General contractors who control the master schedule are reliant on their trades to issue the data needed to populate the master schedule. Some consider this ‘tipping their hand,’ and kneecapping future cost negotiations (change orders.) Unfortunately, very few specialty contractors issue detailed schedules, much less resource loaded schedules. That means the data simply isn’t there to develop a resource loaded schedule. The options then become very few.

The data would ostensibly come from the general contractors estimator, who develops his costs based on production rates. Yet, just like the scheduler, the estimator seldom receives this data from the trades because they either don’t maintain it, or have no interest in sharing what they consider to be proprietary. 

That leaves the last option – a scheduler using cost guides, such as RS Means-  a process which can be hit and miss. But don’t blame the guides: they do a pretty good job estimating production rates. In any case, the scheduler will still need quantified scope of work from his estimator.

As for updating progress in a resource loaded schedule, you need to keep track of production from a unit or physical % complete, as well as actualize start and finish dates. If a  resource loaded schedule is not being used, this is rarely the way progress gets updated, as guesswork is typically invoked. That’s unfortunate, because measured production is the most accurate method of updating a schedule. 

One of the frequent mistakes schedulers male is to conflate or combine physical % with duration %, making it difficult to comprehend work-in-place and planned work. That is especially so when estimating progress is an exercise in guesstimating.

Purists will argue that no schedule can be considered accurate unless it shall be resource loaded. This belief argues for a zero sum equation that is unrealistic, and frankly I’m tired of hearing it: resource based schedules will deliver the most accurate timelines, but that doesn’t mean that they are the only useful timelines, or that we should discard all other work-product  ‘throwing away the baby with the bathwater.’ That is, however, an elementary argument given the circumstance that most schedules can only  boast an accuracy and integrity percentage level in the single-digits.

To be certain, there are entities that will not negotiate the requirement of a resource loaded schedule, as well as projects that simply can’t do without them. Despite that, most projects can be adequately scheduled without resource loading. They may not be as exacting or detailed, but they can convey to a reasonable degree of accuracy the forward-pass. And to be sure, a non-resource loaded schedule is far better than no schedule at all. Thus it is not surprising that the majority of senior schedule roles do not require resource scheduling skills: that’s simply expecting too much..