22-Mec-B4 Integrated Manufacturing Systems · December 2013
Question 6 of 7: Selling Price and Breakeven for the Green Manufacturing Company
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
Notes on this paper
Paper format. National Exams, December 2013 —
07-Mec-B4, Integrated Manufacturing Systems. Three hours; open book;
any non-communicating calculator permitted. Seven questions are printed and any
five constitute a complete paper, each of equal value (20 marks); only the
first five appearing in the answer book are marked. Several questions call for
an essay answer, where clarity and organisation carry marks. Note 1 of the
paper invites the candidate to state any assumption made where a question is
open to interpretation — that licence is used twice below and each use is
flagged. All seven questions are worked here, so the set can
serve as a complete study resource.
Reference texts. Chase, Jacobs & Aquilano,
Operations and Supply Chain Management (McGraw-Hill) — the source
of this paper's forecasting, line-balancing, cost and quality material;
Groover, Automation, Production Systems, and Computer-Integrated
Manufacturing (Pearson) for process planning, cellular manufacturing,
flexible manufacturing systems and plant networks; Montgomery,
Introduction to Statistical Quality Control (Wiley) for the Shewhart
chart constants and the normal-tail scrap calculations; Nahmias & Olsen,
Production and Operations Analysis (Waveland) for the forecasting
derivations; Kalpakjian & Schmid, Manufacturing Engineering and
Technology (Pearson) for the ring-rolling and tolerance context. Canadian
practice for the quality half of the paper follows CSA / ISO 9001 and
the ISO 7870 series on control charts, which tabulate the same constants
used below.
Question 6: Selling Price and Breakeven for the Green Manufacturing Company (20 marks)
Given. A one-year cost and market study for a leased-facility
product line, with selling expenses stated as a percentage of sales revenue
rather than as a fixed sum, and a profit requirement stated per unit.
Given data
Item
Amount
Estimated annual sales
24,000 units
Materials
$96,000
Direct labour
$14,400
Overhead
$24,000
Administrative expenses
$28,000
Selling expenses
15 per cent of sales
Required profit
$1.02 per unit
Find. (a) the unit selling price that recovers all costs and
delivers the required profit; and (b) the breakeven volume in units and in sales
dollars, treating overhead and administrative expense as fixed and everything
else as variable.
Approach. Because selling expense depends on the price being
solved for, write a single revenue equation in which price appears on both sides,
solve it algebraically, then reclassify the same costs into fixed and variable
pools to obtain the contribution margin and hence the breakeven point.
Figure 6.1 — Cost–volume–profit chart at
the price computed below. Total revenue rises at $9.1608 per unit and total
cost at $5.9741 per unit from a fixed base of $52,000; the two lines
cross at 16,318 units and $149,486 of sales. The planned volume of 24,000
units lies well inside the profit region.
Part (a) — total the costs that are independent of price.
Materials, direct labour, overhead and administrative expense are all quoted as
annual sums and none of them depends on the selling price:
$$\text{Cost}_{\text{fixed in }P}=96{,}000+14{,}400+24{,}000+28{,}000=\$162{,}400$$
Selling expense is deliberately excluded here, because it is quoted as a
percentage of sales and therefore changes with the very price being sought.
Write the profit equation with price as the unknown. With
$N=24{,}000$ units and $P$ the unit price, revenue is $NP$, selling expense is
$0.15NP$, and the required profit is $1.02 per unit, so
$$NP=\text{Cost}_{\text{fixed in }P}+0.15NP+1.02N$$
Collecting the price terms,
$$NP(1-0.15)=162{,}400+1.02(24{,}000)=162{,}400+24{,}480=\$186{,}880$$
Solve for the selling price. Dividing by
$N(1-0.15)=24{,}000\times 0.85=20{,}400$,
$$P=\frac{186{,}880}{20{,}400}=9.1608
\qquad\Rightarrow\qquad \boxed{\ P=\$9.16\ \text{per unit}\ }$$
Check the answer by rebuilding the income statement. At
$9.1608 per unit, annual sales are
$24{,}000\times 9.1608=219{,}858.82$ dollars; selling expense is fifteen
per cent of that, $0.15\times 219{,}858.82=32{,}978.82$ dollars; adding the
$162,400 of other costs gives a total cost of $195,378.82, which leaves
$219{,}858.82-195{,}378.82=24{,}480.00$ dollars of profit — exactly
$1.02 per unit on 24,000 units. The price is confirmed.
Part (b) — reclassify the costs as fixed or variable.
The question states that overhead and administrative expenses are fixed and all
other costs vary with volume:
$$F=24{,}000+28{,}000=\$52{,}000\ \text{per year}$$
On a per-unit basis the variable costs are
$$v_{\text{mat}}=\frac{96{,}000}{24{,}000}=\$4.00,\qquad
v_{\text{lab}}=\frac{14{,}400}{24{,}000}=\$0.60,\qquad
v_{\text{sell}}=0.15P=0.15(9.1608)=\$1.3741$$
$$v=4.00+0.60+1.3741=\$5.9741\ \text{per unit}$$
Selling expense is variable by its own definition: it is a fixed proportion of
each sales dollar, so it is a fixed amount per unit sold at a given price.
Form the contribution margin. Each unit sold contributes
$$\mathrm{CM}=P-v=9.1608-5.9741=\$3.1867\ \text{per unit}$$
towards the fixed costs, and the contribution-margin ratio is
$\mathrm{CM}/P=3.1867/9.1608=0.34786$, that is 34.79 per cent of every
sales dollar. Note that the ratio can also be obtained directly as
$0.85-5.10/9.1608$, since 85 per cent of revenue survives the selling
expense and $5.10 per unit is the material and labour content.
Divide the fixed cost by the contribution margin. The
breakeven volume is the point at which accumulated contribution exactly covers
the fixed cost:
$$Q_{\mathrm{BE}}=\frac{F}{\mathrm{CM}}=\frac{52{,}000}{3.1867}=16{,}318
\qquad\Rightarrow\qquad \boxed{\ Q_{\mathrm{BE}}=16{,}318\ \text{units per year}\ }$$
Express the same point in sales dollars. Either multiply the
breakeven units by the price, or divide the fixed cost by the contribution-margin
ratio — the two must agree:
$$S_{\mathrm{BE}}=Q_{\mathrm{BE}}P=16{,}318\times 9.1608=\$149{,}486
\qquad\text{and}\qquad
S_{\mathrm{BE}}=\frac{F}{\mathrm{CM}/P}=\frac{52{,}000}{0.34786}=\$149{,}486$$
$$\boxed{\ S_{\mathrm{BE}}=\$149{,}486\ \text{of sales per year}\ }$$
At the planned volume of 24,000 units the firm therefore operates
$24{,}000-16{,}318=7{,}682$ units above breakeven, a margin of safety of
32 per cent of planned sales — a comfortable but not generous
cushion for a new product.