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Decision tree for plant improvement alternatives

Short answer

Decision tree with three alternatives (A, B, C) and success probabilities evaluated using future worth at 15% for 6 years. Expected FW: A = Rs 860,607, B = Rs 669,292, C = Rs 234,646. Alternative A has the highest expected FW and should be chosen despite a 10% chance of a Rs 12.1 lakh loss.

For the improvement of a manufacturing plant, the following three alternatives are being considered. The estimated investments and the corresponding increment in income are given below. Draw decision tree diagram of the situation and decide on the best alternative using FW formulation. MARR = 15%. Life of the project is 6 years.

AlternativeInvestment CostSalesProbabilityAnnual Income
A1000000High Success0.4500000
A1000000Medium Success0.5300000
A1000000Low Success0.1125500
B600000High Success0.2400000
B600000Medium Success0.5250000
B600000Low Success0.3100000
C400000High Success0.5200000
C400000Medium Success0.1125000
C400000Low Success0.450000

FW at the end of year 6 for each branch = −I(F/P,15%,6) + A(F/A,15%,6), where (F/P,15%,6) = 2.3131 and (F/A,15%,6) = 8.7537. The best alternative is the one with the highest expected FW.

Decision tree

                           ┌ High 0.4  A = 5,00,000
      ┌ Alt A (10,00,000) ─○ Medium 0.5 A = 3,00,000
      │                    └ Low 0.1    A = 1,25,500
      │                    ┌ High 0.2  A = 4,00,000
  □───┼ Alt B (6,00,000) ──○ Medium 0.5 A = 2,50,000
      │                    └ Low 0.3    A = 1,00,000
      │                    ┌ High 0.5  A = 2,00,000
      └ Alt C (4,00,000) ──○ Medium 0.1 A = 1,25,000
                           └ Low 0.4    A = 50,000
  □ = decision, ○ = chance (probability on the branch)

Expected FW of each alternative

Alternative A (investment 1,000,000; FW of investment = 1,000,000 × 2.3131 = 2,313,061)

SalesProbabilityAnnual incomeFW = −I(F/P) + A(F/A)p × FW
High0.4500,0002,063,808825,523
Medium0.5300,000313,061156,530
Low0.1125,500-1,214,467-121,447

E[FW(A)] = 860,607

Alternative B (investment 600,000; FW of investment = 600,000 × 2.3131 = 1,387,836)

SalesProbabilityAnnual incomeFW = −I(F/P) + A(F/A)p × FW
High0.2400,0002,113,659422,732
Medium0.5250,000800,598400,299
Low0.3100,000-512,463-153,739

E[FW(B)] = 669,292

Alternative C (investment 400,000; FW of investment = 400,000 × 2.3131 = 925,224)

SalesProbabilityAnnual incomeFW = −I(F/P) + A(F/A)p × FW
High0.5200,000825,523412,762
Medium0.1125,000168,99316,899
Low0.450,000-487,537-195,015

E[FW(C)] = 234,646

Roll back at the decision node

AlternativeExpected FW (Rs)
A860,607
B669,292
C234,646

Answer: Choose alternative A. It has the highest expected FW (Rs 860,607, equal to PW ≈ Rs 372,064), although it also has the largest downside: a low-success outcome gives FW ≈ −Rs 12.1 lakh with probability 0.1.

✓ Answer checked by Claude Opus 5.5 (high effort)

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