Grey Bedsheets, a Shrunken Sweater and a Flat Rate
A neighbourhood laundry near a boys' hostel runs one 8 kg front-load washer, one dryer and one steam press with two workers, six days a week, 8 hours a day. Weekly volume is 220 kg: hostel bedsheets (white cotton), students' jeans and T-shirts, and a few woollens. The owner charges a flat ₹40 per kg for wash-and-fold and ₹25 per piece for ironing. Last week 30 white bedsheets came back grey, and one student's woollen sweater returned two sizes smaller. Staff say they 'fill the drum to save time' and use one programme for everything. Costs: rent ₹9,000 per month, electricity ₹7 per unit, detergent ₹220 per kg dosed at about 8 g/kg, water and sewer ₹60 per load, worker wage ₹9,000 per month each, and machine depreciation and maintenance ₹3,000 per month. A customer asks for same-day service for 12 shirts.
1. Diagnose the grey bedsheets and the shrunken sweater, link each to a specific workshop practice, and state what you would tell each customer.
Read the worked answer
The two failures have different causes, but both come from using one programme for everything.
- Grey bedsheets: overloading the drum reduces mechanical action and liquor circulation, so soil is loosened but not carried away. Mixing white sheets with jeans and dark T-shirts allows dye transfer and soil redeposition. If rinse water is reused or rinsing is shortened, suspended soil redeposits on the white cloth. Hard water plus an overdose of detergent adds scum. The greyness is therefore a sorting, loading and rinsing failure, not simply 'dirty sheets'.
- Shrunken sweater: wool felts under heat, agitation and alkali. A normal cotton programme supplies all three, and tumble drying completes the damage. The shrinkage is irreversible.
- What to tell the customers: to the hostel, apologise, explain that the sheets were processed with coloured items and will be re-washed with a proper white-cotton programme; offer a credit or re-clean. To the student, admit the error, check whether the sweater had a care label, and follow the compensation policy. Do not blame the student or argue about the label if the label said hand wash and the workshop machine-washed it. Record both complaints and the remedy.
2. Design a sorting and loading SOP with numbers: loads per day, capacity against demand, detergent per load, and programmes for sheets, jeans and woollens.
Read the worked answer
Capacity check: one washer and one dryer, with a wash-plus-dry cycle of about 1.5 hours, give roughly 5 loads per day in an 8-hour day. At 8 kg rated capacity but an 80% working load of 6.4 kg, that is about 32 kg per day, or 192 kg per six-day week. Demand is 220 kg per week, so the current setup is already short of capacity; overloading was an attempt to hide that gap, and it caused the complaints.
Sorting: white cotton; light colours; dark colours and jeans; wool/silk separate. Check pockets, close zips, turn jeans inside out, and pre-treat stains before loading.
Loading: never exceed 6.4 kg for cotton and about 5 kg for bulky sheets. Fill the drum loosely, not packed.
Detergent: at 8 g/kg, a 6.4 kg load needs about 51 g, not a scoop by eye. With hard water, use a built detergent and a sequestrant.
Programmes:
- White sheets: 60 °C, normal agitation, oxygen bleach if needed, three rinses, souring rinse, tumble dry.
- Jeans and T-shirts: 40 °C, inside out, mild detergent, no chlorine, hang dry.
- Woollens: 30 °C wool or hand-wash cycle, neutral detergent, low spin, mesh bag, flat dry; no dryer.
Same-day request: 12 shirts weigh roughly 2–2.5 kg, so they can fit only if a slot is reserved and the dryer is free. Set a cut-off time and a surcharge rather than promising same-day for every walk-in.
3. Using the figures given, calculate the cost per load and per kg, decide whether ₹40/kg is viable, and propose a price for the same-day shirts with justification.
Read the worked answer
Monthly fixed costs: rent ₹9,000 + wages ₹18,000 + depreciation and maintenance ₹3,000 = ₹30,000.
Variable cost per 8 kg load:
- Detergent: 8 g/kg × 8 kg = 64 g at ₹0.22/g = ₹14.08.
- Electricity: washer about 2 kWh, dryer about 3 kWh, press about 0.75 kWh = 5.75 kWh × ₹7 = ₹40.25.
- Water and sewer: ₹60.
- Variable total: about ₹114 per load, or ₹14.3/kg.
Monthly volume: 220 kg/week ÷ 8 kg = 27.5 loads/week × 4.33 = about 119 loads, or about 953 kg.
Full cost: variable ₹114 × 119 = ₹13,566; plus fixed ₹30,000 = ₹43,566 per month. Full cost per kg = ₹43,566 ÷ 953 = about ₹45.7/kg.
Revenue at ₹40/kg: 953 × ₹40 = ₹38,120. The wash-and-fold operation is losing roughly ₹5,400 per month before ironing income. So ₹40/kg is not viable as a full-cost price, although it does cover the marginal ₹14.3/kg if the workshop is otherwise idle.
Recommendation: raise wash-and-fold to ₹55/kg, or introduce a minimum load charge and a white-cotton premium, and improve throughput to spread the fixed labour cost. For same-day 12 shirts, charge the normal rate plus a 30–50% express surcharge, roughly ₹50–75 extra, because the job displaces a scheduled load and may require overtime. Explain the price in terms of capacity and turnaround, not as an arbitrary penalty.