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Convert forecast production volumes into required work-center hours and compare them with site capacity. Use a worked manufacturing example and Excel formulas to expose bottlenecks hidden by company totals.
Demand forecasting and capacity planning translate expected production into required hours, then compare those hours with available time at each constrained resource. Use product-specific processing standards and include setup time once. A company total is useful for reconciliation, but shortages must be resolved where the work will actually run.
The customer forecast is the starting point, not automatically the production quantity. Deduct usable finished stock and existing supply before calculating new output; production planning forecasting works that inventory bridge. The example below assumes no usable finished inventory or existing completions, so all forecast units require new production.
Keep the prediction question separate. Demand forecasting covers estimating the units customers will need. This review asks whether a supplied volume scenario fits the supplied manufacturing capacity.
Choose a resource with a consistent hour definition. Machine hours cannot be compared with labor hours unless an explicit staffing relationship converts them. Here each site has a finishing work center whose processing standards and available schedule are measured in machine hours.
The Federal Reserve's capacity methodology describes capacity as sustainable potential output and utilization as output relative to capacity. The workbook below uses a forward-looking planned load ratio in hours. Label it that way; it is not an observed industry utilization statistic.
An illustrative US manufacturer reviews November 2026 production at Ohio and Texas sites. Both produce pumps and valves, using the same approved processing standards for this example. Engineering owns the standards, operations owns available time, and the production planner owns the supplied demand allocation.
Use a Demand worksheet with the following columns A through G. Setup hours are supplied assumptions for the planned runs and are excluded from the per-unit processing standards.
| Site | Product | Forecast units | Hours per unit | Setup hours | Run hours | Required hours |
|---|---|---|---|---|---|---|
| Ohio | Pump | 600 | 0.40 | 20 | 240 | 260 |
| Ohio | Valve | 200 | 0.60 | 10 | 120 | 130 |
| Texas | Pump | 300 | 0.40 | 15 | 120 | 135 |
| Texas | Valve | 300 | 0.60 | 15 | 180 | 195 |
| Total | 1,400 | 60 | 660 | 720 |
Enter these formulas in F2 and G2 and fill down:
=C2*D2
=F2+E2
The Ohio pump row requires 600 × 0.40 = 240 run hours, plus 20 setup hours, giving 260 hours. The table's 660 run hours plus 60 setup hours reconcile to 720 required hours. All hour quantities in this example are exact; percentages below are rounded to one decimal place.
Use standards for the actual routing and revision. If a product must pass through several constrained work centers, give each operation its own resource row. Do not add those resource capacities together and compare them with just one operation's requirement.
Bring the approved work-center calendar and planned exclusions for the same month. Exclusions can include maintenance, planned closures and time reserved for other work outside this demand scope. Include each exclusion once, and document whether breaks or performance allowances already affect the calendar or standards.
Build a Capacity sheet with columns A through G:
| Site | Scheduled hours | Excluded hours | Net available | Required hours | Headroom | Planned load ratio |
|---|---|---|---|---|---|---|
| Ohio | 500 | 50 | 450 | 390 | 60 | 86.7% |
| Texas | 400 | 80 | 320 | 330 | -10 | 103.1% |
| Total | 900 | 130 | 770 | 720 | 50 | 93.5% |
In D2 through G2, enter and fill down:
=B2-C2
=SUMIFS(Demand!$G$2:$G$5,Demand!$A$2:$A$5,$A2)
=D2-E2
=IF(D2=0,"No capacity",E2/D2)
Microsoft's SUMIFS documentation describes summing values that meet specified criteria. The formula groups required hours by site; add work center and period criteria when the export includes multiple resources or months. Covirage is not affiliated with Microsoft.
Ohio's load is 260 + 130 = 390 hours. Texas requires 135 + 195 = 330. Texas is short 10 hours despite the company having 50 hours of total headroom. Calculate the total ratio as 720 / 770 = 93.5%, rather than averaging the site percentages.
Suppose the planner proposes moving 100 pump units from Texas to Ohio. For this scenario, both sites can use the approved routing, material is available, and the existing runs absorb the change without additional setup hours. Those are assumptions operations must confirm.
The transferred load is 100 × 0.40 = 40 hours. Ohio's required time becomes 390 + 40 = 430, leaving 450 − 430 = 20 hours. Texas becomes 330 − 40 = 290, leaving 320 − 290 = 30 hours. Combined required time remains 430 + 290 = 720, and headroom remains 20 + 30 = 50 hours.
That reconciliation proves this is a relocation of the supplied work. It does not prove shipping dates, staffing or material transfers are feasible. If the move needs another setup, add that requirement before comparing the scenarios.
Reconcile forecast units to the frozen demand file and available hours to the approved calendar. Repeated optimistic volume or allocation assumptions deserve a forecast bias review by product and site. The existing sales capacity arithmetic applies a similar balance to calls and representatives; manufacturing requires its own resource and routing definitions.
Upload a file or Google Sheet containing forecast volumes, production requirements, time standards and site calendars; Covirage maps the columns, and its tools compute and check the comparisons. The external AI model explains the results with every figure traced to its rows. Create a free Covirage account, set up your business and bring a sample of your own data; creating the account takes about a minute.
See Covirage for industrial manufacturers for the industry context.
First reconcile forecast demand with usable inventory and other committed supply to establish required new output. Multiply that output by the applicable processing time at each work center, then add separately planned setup hours. Compare the result with available hours on the same resource and period basis.
Planned load compares forecast required hours with available hours. Actual utilization describes realized activity relative to capacity under a stated definition. Keep the labels distinct: a forward-looking load above capacity identifies a plan requiring review, rather than proving that the factory actually operated beyond capacity.
Hours belong to specific sites, equipment and skills. Spare hours on an incompatible resource cannot satisfy work waiting elsewhere. Aggregate headroom can therefore remain positive while one constrained work center is short. Check approved alternatives, material availability and transfer timing before assuming work can move.
Include setup time once. If per-unit standards exclude setup, add planned setup hours for the expected runs. If the standards already allocate setup time, avoid adding it again. Document the assumption and revise it when a change in batch sizes or product mix changes the expected setups.