Construction schedule acceleration is a strategy designed and intended to either mitigate, or stanch off float erosion (delay), or to recover lost time – so to better control or advance completion dates. There are a number of ways contractors seek to achieve these outcomes. Some are more scientific than others.

Proper schedule acceleration methods rely on CPM schedules with coherent or valid critical paths. Reliable schedules can be modified without compromising integrity. Acceleration schedule logic can be no more efficient than the baselines they modify, thus it is exigent that the project has a coherent schedule. Given the low percentage of reliable schedules, valid acceleration schedules are somewhat of a rarity. This is so for a number of reasons:

Construction schedule acceleration proposes recovery or mitigation of lost time frames through compression in two-ways: enhancing resources, and expediting product deliveries. Typical recovery efforts merely throw additional resources at the project: ‘bomb the job,’ with the assumption that production will increase. They may seek compensation for shift work and overtime, but only when they are not at fault for delay, which is seldom the case. Otherwise, general contractors are reluctant to pay their subs for extra manpower.

The same is true of expediting (red-labeling) product deliveries. All too often I have seen product rushed to a site, only to be reoriented to a warehouse until such time as it is needed on the site. The contractor who owns the product will be stuck for additional transport fees, as well as storage fees.

Enhancing resource strategies through schedule acceleration needs to utilize reliable and feasible production rates. The availability of personnel to meet the increase must be validated: a prime’s scheduler may not unilaterally create a compressed schedule before assurance from trades and suppliers that required resources are available. This can be a challenging endeavor when there are material and manpower shortages.

Another consideration is the availability of space for increased manpower. Too many workers – or ‘trade stacking,’ creates congestion, reduces productivity, and enhances the likelihood of accidents. It is also a big morale stressor:

For example, I remember building an art gallery owner who bullied the general contractor into bombing her project in order to meet an opening date she had moved up several weeks from the contract date. The focus at the time was a  15’ x 30’ foyer with a new level-5 plaster ceiling, and array of recessed 24 or so rectangular Nulux light fixtures. The fixtures had to be dead on aligned as even the slightest misalignment would translate. Despite strings, jet-lines and constant measuring, no array ever properly aligned. The acceleration was an exercise in futility.

The bustling room included some 8 electricians, 2 carpenters, 2 laborers, 4 plasterers, and a scissor lift. The upshot was that the ceiling and lights were continually misaligned and needed to be reinstalled, and finally, a laborer was run into by the scissor jack. After the fiasco, the electrician sent a bill for $25K in extra labor – which as project manager I summarily discarded.

Other problems with trade stacking are that work is installed out of sequence with the plan, which leads to various trades not having access to their work areas when they need it. As they move around or are left standing around, their production rates begin to plummet. Out of sequence work is too often used (unwisely) as a mitigation tool. For example, if sheet metal was not ready, a super might order electricians to pull their wire before the sheetmetal is installed, creating access issues for the tin knockers, insulators, plumbers, and any trades working above the wire.