The Managing Director of NTAMS Manufacturing Company Limited located in Lagos attended a seminar titled “optimising scarce resource utility in a manufacturing setting with particular reference to linear programming”. On his return after three days of the programme, he called for a management meeting to discuss his experiences at the seminar in view of the board decision to produce two major products in the coming years. The following information are made from the work of a research team earlier conducted by a group of external research experts. The expected products are “Biggi” and “smalli”. The expected costs statistics are as follows: Biggis N Smallis N Material costs (5kg @ N50/kg) 250 (3kg @ N50/kg) 150 Labour costs: Machining time (4 hours@ N15/Hr) 60 (2hours @ N15/Hr) 30 Other Processing Time (4hours @ N10/Hr) 40 (5 hours @ N10/Hr) 50 The company expects to maintain a pricing policy that is hinged on total cost of production plus 20% mark up on cost. The Company further expects to incur annual period overhead of N10,000,000 with normal production expectation of 200,000 units of Biggis and 100,000 units of Smallis absorbing the overhead on 3 to 2 basis respectively. It is expected that in the forth coming year, the company will have the following resources available 56 Materials 1,800,000kgs Machine time 800,000 hours Other Process time 1,400,000 hours You are
Explain briefly the concept of linear programming and usefulness of the model
Compute the Prices that will be adopted by the company for the two products using the company pricing policy
Advise the company on the output that needs to be produced to maximise its total profit, supporting your answer with full financial analysis
i. Explain the meaning of ’shadow prices’ and comment on the usefulness of it and its limitation (5 Marks) ii. Calculate the shadow prices of the constraints (7 Marks)
Assuming the company’s position in (c) is maintained for three years with an investment cost of N45,000,000 on the day of the commencement of manufacturing business, using a cost of capital of 15%: i. Can this venture be justified for the period? (4 Marks) ii. What is the breakeven discount factor for this project? (4 Marks)
Revise this question
Limiting factors: allocating a single scarce resource › LayoutsLinear programming: formulation and graphical solution › LayoutsLinear programming: slack and shadow prices › Finding slack and shadow pricesCost-based pricing: cost-plus and relevant-cost pricing › Layouts for cost-based pricesSuggested answer
a. Concept of linear programming and usefulness Linear programming is a mathematical method for determining a way to achieve the best outcome (such as maximum profit or lowest cost) subject to a number of limiting factors (constraints). A linear programming problem involves maximising or minimising a linear function (the objective function) subject to linear constraints. Both the constraints and the “best outcome” are represented as linear relationships. What constitutes the best outcome depends on the objective. The equation constructed to represent the best outcome is known as the objective function. Uses of linear programming (LP)
• Budgeting: In preparing budget, one of the first steps is the identification of the key (limiting) factor. When there is more than one limiting factor, LP can be used to identify the most profitable use of resources.
• Capital budgeting: When we have multi-period capital rationing, LP can be used to optimally allocate the available funds among the competing projects.
• Transfer pricing: In a divisionalised organisation, LP can be used to compute optimal transfer price between divisions when the supplying division does not have sufficient capacity to met all the demands placed upon it.
• Calculating relevant costs: The relevant cost of a scarce resource is calculated as acquisition cost of the resource plus opportunity cost. When more than one scarce resource exist, LP can be used to establish the opportunity cost (Shadow price).
• Maximum payment for the supply of additional scarce resources: If labour is an effective limiting factor, for example, the maximum overtime premium to pay per additional hour is the shadow price which can be determined using LP.
• Control: LP is also useful in the analysis of variances. For example, adverse material usage variances can be indication of material wastage. Such variances 68 should be valued at the standard cost of the material plus the opportunity cost of the loss of one scarce unit of material. LP can be used to determine the opportunity cost.
b. Computation of unit selling price and associated unit profit of the two products. Biggis N Smallis N Material 250 150 Labour costs: Machine time 60 30 Processing 40 50 Overhead cost 30 40 Total costs 380 270 Profit per unit 76 54 Selling price per unit 456 324
c. ADVICE ON THE OUTPUT TO BE PRODUCED TO MAXIMISE TOTAL PROFIT STEP 1 –DETERMINATION OF LIMITING FACTOR Materials needed to produce 200,000 units of Biggis & 100,000 units of Smallis BIGGIS 5kg x 200,000 1,000,000 SMALLIS 3kg x 100,000 300,000 Total Required 1,300,000 Available Material 1,800,000 Conclusion: Materials are not limiting factor since available resources exceed resources needed to meet production levels. Machine time needed to produce 200,000 units of Biggis and 100,000 units of Smallis. 69 BIGGIS 4hrs x 200,000 800,000 SMALLIS 2hrs x 100,000 200,000 Total Required 1,000,000 Available Hours 800,000 Conclusion: Machine time is a limiting factor since hours available are less than the hours needed to meet production levels. Other processing time needed to produce 200,00 units of Biggs and 100,000 units of smallis: BIGGIS 4hrs x 200,000 800,000 SMALLIS 5hrs x 100,000 500,000 Total Required 1,300,000 0 Available Hours 1,400,000 Conclusion: Other processing time is not a limiting factor since hours available exceeds hours needed to meet production levels. STEP 2 – DETERMINATION OF PRIORITY OF PRODUCTION PLAN Biggis Smallis N N Selling price 456 324 Total variable costs (350) (230) Contribution per unit 106 94 Machine time per unit 4 2 Contribution per machine time 26.5 47 Ranking 2nd 1st PRODUCT UNITS HOURS USED HOURS LEFT SMALLIS 100,000 200,000 600,000 BIGGIS 150,000 600,000 - 70 Comment Hence, the optimal production plan for NTAMS Manufacturing Company Ltd is to produce 100,000 units of Smallis and 150,000 units of Biggis.
(d) SHADOW PRICE MEANING The shadow cost of a binding constraint is the amount by which the objective function decreases (or increases) as a result of availability of one unit less or more of the scarce resource. The solutions to the dual problem of the primal problem give the shadow costs (prices), hence the alternative term dual costs (prices). USEFULNESS OF SHADOW PRICES
• Can be used to determine the relevant cost of a scarce resource
• Useful in setting transfer price
• Useful in setting transfer price
• It assists in determining opportunity cost
• Can be used in allocating funds to projects when there is multi-period capital rationing. The major limitation of shadow price is that it is valid for a limited range of output. For example, if labour hour is the limiting factor, the shadow price will tend to zero as more labour hours are supplied. 71 CALCULATION OF SHADOW PRICE OF THE CONSTRAINTS Shadow price only exists for binding resources – hence shadow price will only exist for machine time. If one (1) additional machine time is available, total machine time will be 800,001 Total units of Biggis to be produced wil l be 150,000.25 units (600,001/4) New Total contribution will be (100,000 x 94) + (150,000.25 x 106) = 25,300,026.50 Previous total contribution was (100,000 x 94) + (150,000 x 106) = 25,300,000 Increase in contribution = 25,300,026.50 – 25,300,000 = 26.50 Alternative solution Candidates may reduce the available machine time by 1 hour. If one machine hour is reduced Total units of Biggis =149,999.75 units N New contribution (100,000 x 94 + 149,999.75 x 106) = 25, 299,973.5 Old contribution 25,300,000 Shadow price (reduction in contribution) (26.50) Shadow price = N26.50k
ei) NPV (Discount Factor 15%) = 2.283 Total contribution = 25,300,000 (2.283) = 57,759,900 Total Outflow = 45,000,000 = 45,000.000 NPV = N12,759,000 Yes, the project’s NPV is positive and therefore worthwhile.
ii) If a discount factor = 35% Total contribution = 25.300,000 x 1.696 = N42,908,800 Total Outflow = N 45,000,000 NPV at 35% = (N2,091,200) IRR = a + ( BA
- A) (b – a) 72 a = Positive NPV discount rate A = Positive NPV b = Negative NPV discount rate B = Negative NPV = 15% + ( 200,091,2000,759,12 000,759,12 \+ ) (35% – 15%) = 15% + ( 000,759,12 100,851,14 ) (20%) = 15% + 17.18% = 32.18%
Examiner’s report The question tests students’ understanding of resource allocation using contribution per limiting factor. It was attempted by the majority of the candidates being a compulsory question. The performance was below average. The major pitfall was the lack of understanding in the subject area and the conditions that must be satisfied before the linear programming is applied. Candidates are advised to read the ICAN study text when preparing for future examination of the Institute.
Marking guide Mark Total a. Definition of linear programming 1 Explanation of linear programming 1 Usefulness (3 points at 1 mark per point) 3 5 b. Selling Price (20 ticks at ¼ mark per tick) 5 c. Advice on the optimal output 10 d. Shadow Price/usefulness/limitation 5 Shadow price computations 7 12 e. Investment analysis - NPV 4 Calculation of IRR 4 8 40 73
SECTION B