Calculation and scope notes

Calculation baseline

Professional web version 1.0 follows the OR 001 Professional workbook v8.1. Keep assumptions in their owning inputs. If you transfer a workload to True Cost, change volume and operating days in Workload and transfer the updated case again.

Quick Workload

Rooms × average occupancy × kg per occupied room, plus the entered additional daily streams. Divide by staffed operating hours for average required throughput. Free excludes rewash, peaks, buffers and equipment assumptions.

Full Workload

Measured guest-room kg divided by measurement-period occupied room-nights takes precedence over planning intensity when positive. Average and peak guest-room volumes are calculated separately. Eight ancillary streams have their own average and peak volumes.

Planning rewash r means additional rewash kg ÷ first-pass kg. Stream overrides take precedence over the default. The KPI fraction q means rewash kg ÷ total processed kg: r = q / (1 − q). Apply the design buffer after peak processed demand. Annual volume uses average processed demand × hotel open days.

Laundry days/week is contextual in the workbook; it does not introduce a 7/days multiplier. Model backlog from closed laundry days explicitly in design inputs and the staffed window.

Quick Cost

Sum entered annual direct costs and optional annual equipment cost. Compare with annual kg × vendor rate. It omits the detailed equivalent-scope adjustments, capital recovery, space, handling, textile costs and minimum-charge logic available in Professional.

True Cost

Direct labour is hours/day × hotel open days × loaded hourly cost. Water and sewer use L/kg ÷ 1,000 × price/m³ × annual kg. Energy uses kWh/kg × price/kWh × annual kg. Annual capital cost uses the capital recovery factor after deducting discounted residual value. Zero discount uses straight-line annualisation. Space uses m² × annual opportunity cost/m².

Outsourced processing is the larger of kg × rate and the minimum annual charge, plus surcharges and the other system costs. Inventory carrying cost remains in the workbook’s outsourced economic total; the web additionally identifies cash cost by excluding that carrying charge. Include hotel-owned textile wear and loss on both sides, or enter the full rental service and remove charges already included in the supplier price.

The indicative break-even rate excludes minimum-charge effects. The web flags when the minimum prevents that result from being attainable. Sensitivities change one stated driver at a time, holding other inputs constant; the labour scenario varies direct OPL production labour only, as in the workbook.

Quick and full audit

The Quick Audit selects 14 of the 50 controls and gives each equal weight: achieved points ÷ 28. It provides a few priorities. Professional retains all original control texts and risk weights, scoring each response 0, 1 or 2. Weighted score = sum(score × risk weight) ÷ sum(2 × risk weight). A score is only shown once all required controls are answered. Prioritise weight-3 gaps before other deficits.

Display rounding does not change calculation precision. All kg-to-lb conversions use 2.2046226218.

Decision support only. These resources are not engineering design, professional engineering, legal or regulatory advice, manufacturer specifications, or a guarantee of savings or operational results.