The load plan, or RCCP (rough-cut capacity planning), is the feasibility check that compares the load demanded by the master schedule to the capacity truly available, period by period, on critical resources. It answers a single but decisive question: is the plan we just built even achievable?
Why it matters
A master schedule can look perfectly coherent on paper, balancing demand and stock to the unit, yet crash on a plain reality: the factory physically cannot produce these volumes in these lead times. Without a load plan, this impossibility only becomes visible at detailed scheduling, or worse, in production, when it is too late to react calmly. The bottleneck is then discovered under pressure, express freight and overtime are improvised, and the fine plan collapses.
The load plan is the early warning that avoids this scenario. By confronting load with capacity early, it surfaces overloads while they are still cheap to fix: add a shift, pull volume earlier, level the load or adjust the master schedule, weeks before the order reaches the floor. It is the difference between steering and enduring. It sits between strategic planning and fine scheduling: coarser than the latter, but accurate enough to settle the only question that matters at this stage, feasibility.
The wisdom of the load plan lies in a counter-intuitive principle: do not look at everything. You do not check every machine, only the bottleneck resources, those that truly constrain the flow: the critical line, the specialized furnace, the rare crew, the limited supplier. Trying to model every resource turns a fast tool into an unmanageable gas factory.
The other expert lesson concerns real capacity versus theoretical capacity. Planning at 100% availability, as if machines never broke down and never changed over, produces a plan mathematically clean but operationally false. Useful capacity integrates real yield (the famous OEE), downtime, hazards. An honest load plan counts the capacity you truly have, not the one you dream of.
The mechanism
The principle is deliberately simple: convert the master schedule into load hours on each critical resource, set available capacity against it, and compare the two each period.
On the chart, each bar is the load of one period on the bottleneck resource, expressed as a percentage of capacity. The horizontal line is available capacity: the ceiling. As long as bars stay under the line, the plan passes, the resource absorbs the load. The moment a bar crosses it, it turns red: an overload, the plan is not achievable as is in that period.
This visual reading is exactly what the planner seeks. It locates the problem in time (which periods) and space (which resource), and quantifies it (by how much it exceeds). The underlying calculation is elementary: a period's load is the planned quantity times the standard time per unit on the bottleneck. Divided by capacity, it gives a load ratio, below 1 or above. Nothing sophisticated, but immediate decision power.
Facing an overload, the planner has two symmetric levers: increase capacity (add a shift, subcontract, hire) or reduce load (pull volume earlier or later into slack periods, adjust the master schedule, revise the product mix). Facing chronic under-load, the trade-off reverses: resource is wasted, either cut it or find it work. The load plan does not decide for the planner; it makes the decision visible and quantified.
Figure 1. Load per period compared to available capacity. Bars crossing the line (in red) signal an overload: the plan is not feasible in those periods. Illustrative schematic.
The traps
The load plan misleads when it models the shop floor's reality poorly.
Planning at 100% theoretical availability, ignoring downtime, changeovers and real yield (OEE), produces a plan that looks feasible but is not. The capacity to use is the one truly obtained, hazards included, not the machines' nominal maximum.
The load plan is deliberately coarse: it looks at bottlenecks, not every work center. Adding all resources turns it into a heavy gas factory, slow to recompute, and paradoxically less used. The right granularity is that of the real constraints.
Load is computed from standard times per unit. If these times are never reconciled with real shop-floor data (MES, OEE), they age and skew the whole calculation. Up-to-date parameters are the condition of a credible load plan.
Computing it
Building a load plan follows a clear sequence, centered on the resources that truly matter.
Spot the critical resources that truly constrain the flow: the saturated line, the specialized machine, the rare crew, the limited supplier. It is on these, and these alone, that the load plan focuses.
For each period, convert the master schedule's quantities into hours on each bottleneck: quantity times standard time per unit, accumulated over all products passing through the resource.
Estimate the hours each bottleneck truly offers: number of shifts, duration, corrected for real yield and foreseeable downtime. This is the honest ceiling, not the theoretical maximum.
Confront load and capacity period by period (see formula). On overloads, decide: increase capacity or level the load. On under-loads, cut the resource or fill it. Recompute at each master-schedule update.
Neighboring concepts
The load plan validates the master schedule and extends S&OP logic toward capacity.
From knowledge to action
A plan coherent on paper can be infeasible on the floor. Our Planning, Forecasting & S&OP file installs the load plan that reveals your bottlenecks before they hurt.