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22-Mec-B4 Integrated Manufacturing Systems · May 2016

Question 6 of 6: Break-Even Analysis and the Present Value of an Equipment Investment

Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)

Notes on this paper

Paper format. National Exams, May 2016 — 07-Mec-B4 Integrated Manufacturing Systems. Three hours, open book, any non-communicating calculator permitted. Six questions are printed; any five constitute a complete paper and only the first five appearing in the answer book are marked, each of equal value (20 marks). All six are solved here, because the complete set is the study resource. Questions 1(b)–(d) and the whole of Question 4 are essay questions, in which the examiners award marks for clarity and organisation as well as for content.

Reference texts. E. S. Buffa and R. K. Sarin, Modern Production / Operations Management, 8th ed. (inventory systems, economic order quantity, information feedback, break-even and investment analysis); A. J. Duncan, Quality Control and Industrial Statistics, 5th ed. (error of measurement, gage and inspector variability, precision and accuracy); D. C. Montgomery, Introduction to Statistical Quality Control, 8th ed. (measurement systems analysis, process capability); C. E. Ebeling, An Introduction to Reliability and Maintainability Engineering, 3rd ed. (exponential and normal life models, maintainability); R. B. Chase and F. R. Jacobs, Operations and Supply Chain Management, 16th ed. (components of demand, adaptive forecasting); S. Nahmias and T. L. Olsen, Production and Operations Analysis, 7th ed. (forecasting methods, inventory control under uncertainty); M. P. Groover, Automation, Production Systems, and Computer-Integrated Manufacturing, 5th ed. (integrated manufacturing systems, production planning).

Note on this sitting. Question 4 is reissued word for word from the May 2013 paper (its Question 1), and Question 6 is reissued word for word from the May 2014 paper (its Question 3). The full working is transcribed in place below rather than cross-referenced, so this file stands alone.

Question 6: Break-Even Analysis and the Present Value of an Equipment Investment (20 marks)

Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.

Given. A product whose cost structure is stated over a defined output range, at two alternative selling prices; and a machine whose first cost, life, salvage value, annual operating cost and interest rate are all stated.

Given data — Question 6
QuantitySymbolValue
Fixed cost per period, part (a)FC$25,000
Variable cost per unitv$10
Original selling pricep1$20
Increased selling pricep2$25
Output range over which the cost data holdQ1,500 to 2,500 units
First cost of the machine, part (b)P$24,000
Economic lifen8 years
Salvage value at year 8F$4,000
Annual operating costAoc$3,000 per year
Interest ratei10 per cent per year

Find. (a) the break-even output at each of the two selling prices and the effect of the price increase, and (b) the present value of the expenditures charged to the new machine.

010002000300040000250005000075000100000output Q (units per period)dollars per periodQ = 2500Q = 1667fixed costrevenue at the higher pricerevenue at the original pricetotal cost
Break-even chart for the product. Raising the price rotates the revenue line about the origin and moves the break-even point from 2,500 units to 1,667 units.

Approach. Part (a) equates revenue with total cost, so the break-even output is the fixed cost divided by the contribution per unit; part (b) discounts each cash flow to time zero with the standard series and single-payment factors and sums them.

  1. Part (a) — write the break-even condition. At break-even, revenue equals total cost, so $$pQ = FC + vQ \quad\Longrightarrow\quad Q_{BE} = \frac{FC}{p-v}$$ The denominator is the contribution per unit, the money each unit leaves behind after paying its own variable cost.
  2. Evaluate at the original price. With a contribution of $20-10 = 10$ dollars per unit, $$Q_{BE,1} = \frac{25{,}000}{20-10} = 2{,}500\ \text{units}$$ $$\boxed{Q_{BE,1} = 2{,}500\ \text{units, at a revenue of 50,000 dollars}}$$ This sits exactly at the top of the 1,500 to 2,500 unit range over which the cost data are stated, so the plant only just breaks even at the highest output for which the answer is valid.
  3. Evaluate at the increased price. Raising the price to 25 dollars raises the contribution to 15 dollars per unit, half as much again, so $$Q_{BE,2} = \frac{25{,}000}{25-10} = 1{,}666.7\ \text{units}$$ $$\boxed{Q_{BE,2} = 1{,}667\ \text{units (rounded up), at a revenue of 41,667 dollars}}$$ A fractional unit cannot be sold, so the break-even quantity is always rounded up: at 1,666 units the operation is still a few dollars short.
  4. State the effect of the price increase. The break-even output falls by $2{,}500-1{,}667 = 833$ units, that is by 33.3 per cent, and the break-even revenue falls from 50,000 to 41,667 dollars. The reason the quantity falls proportionally further than the price rises is that the price increase of 25 per cent lands entirely on the contribution, which is only half the price, so contribution rises by 50 per cent and the break-even quantity falls by the reciprocal factor. Equivalently, at the 2,500-unit ceiling the higher price now yields a profit of $2{,}500(25) - \left[25{,}000+10(2{,}500)\right] = 12{,}500$ dollars instead of nothing at all.
  5. Part (b) — identify the cash flows and their factors. Three flows are charged to the machine: the first cost of 24,000 dollars at time zero, an operating cost of 3,000 dollars at the end of each of eight years, and a salvage receipt of 4,000 dollars at the end of year eight. At 10 per cent, $$(P/A,10\%,8) = \frac{1-(1.10)^{-8}}{0.10} = 5.3349 \qquad (P/F,10\%,8) = (1.10)^{-8} = 0.46651$$
  6. Discount and sum. The operating series is worth $3{,}000(5.3349) = 16{,}004.78$ dollars today and the salvage receipt is worth $4{,}000(0.46651) = 1{,}866.03$ dollars today, so $$PV = 24{,}000 + 16{,}004.78 - 1{,}866.03$$ $$\boxed{PV = 38{,}138.75\ \text{dollars}}$$ The salvage value is a receipt and therefore carries the opposite sign to the two disbursements.
  7. Express the answer as an equivalent annual cost. Spreading that present value uniformly over the eight-year life gives $$EUAC = PV\,(A/P,10\%,8) = \frac{38{,}138.75}{5.3349} = 7{,}148.88\ \text{dollars per year}$$ which is the figure to compare against a rival machine of a different life, since present values may only be compared over equal study periods.
012345678end of yearfirst cost 24,000operating cost 3,000 per yearsalvage 4,000Cash flows charged to the new machine (10 percent per year)Downward arrows are disbursements; the upward arrow is the salvage receipt.
Cash flows charged to the new machine over its eight-year life, drawn on the end-of-year convention used by the discount factors.
Final results — Question 6
QuantityValue
Contribution per unit at $20$10
Break-even output at $202,500 units
Break-even output at $251,666.7, say 1,667 units
Reduction in break-even output833 units, 33.3 per cent
Break-even revenue at the two prices$50,000 and $41,667
(P/A, 10 per cent, 8)5.3349
(P/F, 10 per cent, 8)0.46651
Present value of the operating series$16,004.78
Present value of the salvage receipt$1,866.03
Present value of expenditures on the machine$38,138.75
Equivalent uniform annual cost$7,148.88 per year
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