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22-Mec-B4 Integrated Manufacturing Systems · May 2014

Question 3 of 8: Break-even Analysis and Present Value of an Equipment Decision

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

Notes on this paper

Paper format. National Exams, May 2014 — 07-Mec-B4 Integrated Manufacturing Systems, 3 hours, OPEN BOOK, any non-communicating calculator permitted. Eight questions are printed; any five constitute a complete paper and each question is of equal value (20 marks). Only the first five answers appearing in the answer book are marked. All eight are solved here.

Reference texts. R. Chase and F. R. Jacobs, Operations and Supply Chain Management, 16th ed. (forecasting, work measurement, break-even, process control); S. Nahmias and T. Olsen, Production and Operations Analysis, 7th ed. (lot sizing, inventory control); E. S. Buffa and R. K. Sarin, Modern Production / Operations Management, 8th ed. (the requirements-schedule lot-size comparison of Question 4); D. C. Montgomery, Introduction to Statistical Quality Control, 8th ed. (Shewhart charts and capability); M. P. Groover, Automation, Production Systems, and Computer-Integrated Manufacturing, 5th ed. (materials handling, group technology coding, CAPP and CAD); B. W. Niebel and A. Freivalds, Methods, Standards, and Work Design, 13th ed. (time study, allowances, wage-incentive plans).

Question 3: Break-even Analysis and Present Value of an Equipment Decision (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. Part (a) is a single-product cost-volume-profit model valid over the output range 1,500 to 2,500 units; part (b) is a deterministic present-worth calculation over an eight-year life at 10 percent.

Given data
ItemSymbolValue
Fixed cost per period (a)$F$$25,000
Variable cost per unit (a)$v$$10 per unit
Selling price, base case / revised (a)$p$$20 / $25 per unit
Valid output range (a)—1,500 to 2,500 units
First cost of machine (b)$P$$24,000
Economic life (b)$n$8 years
Salvage value at year 8 (b)$S$$4,000
Annual operating cost (b)$C$$3,000 per year
Interest rate (b)$i$10 percent per year

Find. The break-even output at each of the two prices and the effect of the price increase; and the present value of all expenditures on the machine over its eight-year life.

Break-even chart015,00030,00045,00060,00075,00006001,2001,8002,4003,000Output, units per periodDollars per periodfixed costtotal costrevenue at 20 per unitrevenue at 25 per unitBEP 2,500 unitsBEP 1,667 units
Cost-volume-profit chart for part (a). Raising the price from 20 to 25 dollars steepens the revenue line, so it crosses the total-cost line further to the left and the break-even output falls by one third. The revised break-even lies below the 1,500-unit lower limit of the stated cost range, which is the point the answer must make.

Approach. Part (a): set revenue equal to total cost and solve for volume, then repeat at the higher price and test the answer against the range over which the cost model was stated to hold. Part (b): discount the operating annuity with the series present-worth factor, discount the salvage receipt with the single-payment present-worth factor, and add them to the first cost with the correct sign.

  1. Part (a) — write the break-even condition. Break-even is the output at which contribution exactly absorbs the fixed cost, $pQ=F+vQ$, so $$Q_{BE}=\frac{F}{p-v}$$ where $p-v$ is the contribution margin per unit. At the stated price the margin is $20-10=10$ dollars per unit.
  2. Evaluate at the base price. Substituting the given data, $$Q_{BE}=\frac{25{,}000}{20-10}=\boxed{2{,}500\ \text{units per period}}$$ corresponding to break-even revenue of $$2{,}500\times\$20=\$50{,}000$$ This result sits exactly on the upper limit of the range over which the cost model was stated, so it is admissible but only just; at any higher volume the fixed cost of $25,000 would have to be re-examined for a step increase.
  3. Re-evaluate at the increased price. Raising the price to $25 widens the contribution margin to 15 dollars per unit while leaving both cost parameters untouched, so $$Q_{BE}^{\prime}=\frac{25{,}000}{25-10}=1{,}666.7\;\Rightarrow\;\boxed{1{,}667\ \text{units per period}}$$ at a break-even revenue of about $41,667. The break-even output falls by 833 units, one third of its former value, because the margin rose by one half and break-even volume varies inversely with margin.
  4. Interpret the shift, and note the range restriction. The firm now covers its fixed cost 833 units sooner, so every unit of the old 2,500-unit break-even volume beyond 1,667 becomes profit, and the margin of safety at any given sales level widens. Two qualifications belong in the answer. The revised break-even of 1,667 units lies below the 1,500-unit floor of the stated validity range only if output falls below 1,500, which it does not; but at 1,667 units the firm is operating near the bottom of the range where the $25,000 fixed cost was measured, so the linear model should be re-fitted before the result is used for a pricing decision. More importantly, the calculation assumes the quantity sold is unaffected by the 25 percent price rise. If demand is elastic, the lower break-even volume may still be harder to reach than the higher one was, and that trade-off, not the arithmetic, is the real decision.
Cash-flow diagram, dollars (costs down, receipts up)012345678year24,000annual operating cost 3,000 per yearsalvage 4,000
Cash-flow diagram for part (b). One outlay of 24,000 dollars at time zero, an eight-year operating annuity of 3,000 dollars per year, and a 4,000-dollar salvage receipt at the end of year 8, all discounted at 10 percent.
  1. Part (b) — assemble the three cash-flow components. The present value of net expenditure is the first cost, plus the present worth of the operating annuity, less the present worth of the salvage receipt: $$PV=P+C\,(P/A,i,n)-S\,(P/F,i,n)$$ Costs are taken as positive because the question asks for the present value of expenditures; the salvage value is a receipt and therefore carries the opposite sign.
  2. Evaluate the two interest factors at 10 percent for eight years. The series present-worth factor and the single-payment present-worth factor are $$(P/A,10\%,8)=\frac{1-(1.10)^{-8}}{0.10}=5.3349,\qquad (P/F,10\%,8)=(1.10)^{-8}=0.46651$$ These are the standard tabulated values; recomputing them from the compound-interest definition rather than reading them off a table avoids the interpolation errors that creep in when a table stops at a different life.
  3. Discount each component. The operating annuity is worth $$3{,}000\times5.3349=\$16{,}004.78$$ today, and the salvage receipt is worth $$4{,}000\times0.46651=\$1{,}866.03$$ today. The salvage is worth less than half its face value because it is eight years away at 10 percent, which is why salvage rarely decides an equipment choice.
  4. Combine to obtain the present value of expenditures. Adding the first cost and the discounted operating costs and subtracting the discounted salvage, $$PV=24{,}000+16{,}004.78-1{,}866.03=\boxed{\$38{,}138.75}$$ It is worth converting this to an equivalent annual cost for comparison with alternatives of different lives: multiplying by the capital-recovery factor $(A/P,10\%,8)=0.187444$ gives $7,148.88 per year. Any competing machine whose equivalent annual cost is below that figure is the better buy at 10 percent.
Question 3 — results
QuantityValue
(a) Break-even output at $20 per unit2,500 units (revenue $50,000)
(a) Break-even output at $25 per unit1,667 units (revenue $41,667)
(a) Effect of the price increasebreak-even falls by 833 units, a reduction of 33.3 percent
(b) Present worth of operating costs$16,004.78
(b) Present worth of salvage$1,866.03
(b) Present value of net expenditures$38,138.75
(b) Equivalent annual cost$7,148.88 per year