Quoting and scheduling 1,500 case-bound account books in 20 days
A workers' cooperative invites a rate for 1,500 A4 account books, 200 pages (100 leaves) of 80 gsm paper, case-bound with 2.5 mm board and rexine spine and corners, delivered in 20 working days. The workshop has four production workers, one of whom uses a wheelchair and works at a lowered table, one guillotine, one board shears, one two-head wire stitcher, one nipping press and one casing-in jig. Records from a similar 500-copy job show output of 60 books a day with the same four workers when board was cut by hand; the shears is now motorised, and the supervisor believes this adds 20% to the case-making stage only, which is 40% of the total work. Material prices: 70 × 100 cm 80 gsm paper at ₹4.50 a sheet; 2.5 mm board at ₹120 for a 1 × 1.5 m sheet; rexine at ₹210 a metre (1.4 m wide) with 0.09 m² per book; PVA at ₹180 a kg using 25 g per book. The cooperative's budget rate is ₹95 a book and it will not extend the 20 days.
1. Estimate the paper and board required with wastage, and the number of days the job will take. Identify the bottleneck.
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Paper. Eight A4 leaves come from one 70 × 100 cm sheet. 100 leaves per book ÷ 8 = 12.5 sheets. For 1,500 books: 18,750 sheets. With 8% wastage for guillotine trim, damaged sheets and make-ready: 18,750 × 1.08 = 20,250 sheets, i.e. about 20,250 × ₹4.50 = ₹91,125.
Board. One board piece is 31 × 22 cm = 0.0682 m²; two per book = 0.1364 m². One board sheet is 1.5 m², so 1.5 ÷ 0.1364 = 10.99, i.e. 11 books per sheet if the cutting layout is efficient. 1,500 ÷ 11 = 136.4, round to 137; with 8% wastage, 148 sheets.
Time. Baseline 60 books a day gives 1,500 ÷ 60 = 25 days. The case-making stage is 40% of that time; a 20% speed-up reduces it to 40 ÷ 1.2 = 33.3%, so total time falls to 66.7 + 33.3 = 100 − 6.7 = 93.3% of baseline. New output ≈ 60 ÷ 0.933 = 64.3 books a day, and 1,500 ÷ 64.3 = 23.3 days.
Bottleneck. 20 days demands 75 books a day against 64 achievable - a 17% shortfall of about 3.3 days. The constraint is not the guillotine but the two-head stitcher and the single nipping press, which are occupied by every book and cannot be duplicated within the budget. The wheelchair user's lowered table is not a constraint provided the work is presented within reach.
2. Propose a plan that finishes in 20 days, with numbers, and state what you would refuse to compromise on.
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Plan, in the order that saves most time per rupee:
- Pre-cut materials in the first three days. Cut all 20,250 sheets and 148 board sheets before any book is stitched, so the guillotine is never waiting for a second operation. Roughly three days of one worker.
- Overtime. Two extra hours a day for four workers over 20 days adds 8 hours a day to a 32-hour day, i.e. 25% capacity, which covers the 17% gap with margin. Pay it and record it.
- Split the line. Two workers on stitching and pressing, two on case-making and casing-in, with covers pre-made in week one. The casing-in jig must be loaded from the front so the wheelchair user is not reaching across it.
- Subcontract only if overtime is refused. Place 300 books with a nearby unit at about ₹18 a book (₹5,400), which clears the gap without touching the delivery date.
Refuse to compromise on: grain direction in the board and paper, a single spine width across the whole run so the covers all match, fresh PVA with a full 24-hour cure, and machine guards. Do not remove the shears guard or the stitcher guard to gain speed, and do not lower the wheelchair user's table height to suit a standing worker. Safety and grain direction are the two places where a rushed order turns into a returned order.
3. Test the ₹95 rate against the material cost and advise the cooperative and your supervisor.
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Material cost per book, using the bought quantities rather than the theoretical ones:
- Paper: 20,250 sheets × ₹4.50 ÷ 1,500 = ₹60.75
- Board: 0.1364 m² at ₹80 per m² (₹120 ÷ 1.5 m²) = ₹10.90
- Rexine: 0.09 m² at ₹150 per m² (₹210 ÷ 1.4 m width) = ₹13.50
- PVA: 25 g at ₹0.18 per g = ₹4.50
- Subtotal material = ₹89.65
Add wire, thread, headbands, packing and transport (say ₹4) and the figure is about ₹94 - before one rupee of labour, power, rent or machine depreciation.
Verdict: at ₹95 a book the order destroys working capital. It cannot be accepted on these terms. The realistic ex-works rate, with labour at the 25-day baseline, overhead and a 10% contingency, sits near ₹135–145 a book.
Advice to the cooperative: submit a one-page cost sheet with the quote showing material at ₹94, labour hours and the contingency, and offer two options - the specified book at ₹140, or a reduced specification (70 gsm paper, paper-backed cloth instead of rexine) at about ₹118. If the rate is fixed at ₹95, decline in writing and quote for the next tender instead. Accepting a loss-making first order is the commonest reason small binding units fail in their second year, and a reference customer at a fair rate is worth more than a large order at a loss.