Industrial Engineering Miscellaneous Easy Questions and Answers | Page - 14

Industrial Engineering Miscellaneous

A moving average system is used for forecasting weekly demand. F₁ (t) and F₂ (t) are sequences of forecasts with parameters m₁ and m₂, respectively, where m₁ and m₂ (m₁ > m₂) denote the numbers of weeks over which the moving averages are taken. The actual demand shows a step increase from d₁ to d₂ at a certain time. Subsequently,

1. neither F₁ (t) and F₂ (t) will catch up with the value d₂
1. both sequences F₁ (t) and F₂ (t) will reach d₂ in the same period
1. F₁ (t) will attain the value d₂ before F₂ (t)
1. F₂ (t) will attain the value d₂ before F₁ (t)

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Given that, at certain the demand increased from d₁ to d₂
The weight age of the latest demand should be there face f₂ (t) become M₂ > M₂.

Correct Option: D

Given that, at certain the demand increased from d₁ to d₂
The weight age of the latest demand should be there face f₂ (t) become M₂ > M₂.

In an MRP system, component demand is

1. forecasted
1. established by the master production schedule
1. calculated by the MRP system from the master production schedule
1. ignored

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calculated by the MRP system from the master production schedule

Correct Option: C

calculated by the MRP system from the master production schedule

The sales of a product during the last four years were 860, 880,870 and 890 units. The forecast for the fourth year was 876 units. If the forecast for the fifth year, using simple exponential smoothing, is equal to the forecast using a three period moving average the value of the exponential smoothing constant α is

1. 1/7
1. 1.5
1. 2/7
1. 2/5

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F₄ = 876 units

F₅ = F₃
F₃ = 890 + 870 + 880
2

F₅ = F₄ + α (D₄ – F₄)
880 = 876 + α (890 – 876)
α = 2
7

Correct Option: C

F₄ = 876 units

F₅ = F₃
F₃ = 890 + 870 + 880
2

F₅ = F₄ + α (D₄ – F₄)
880 = 876 + α (890 – 876)
α = 2
7

For a product, the forecast and the actual sales for December 2002 were 25 and 20 respectively. If the exponential smoothing constant (α) is taken as 0.2, the forecast sales for January 2003 would be

1. 21
1. 23
1. 24
1. 27

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F_t+1 = F_t + α (D_t – F_t)
F_{Jan (2003)} = F_Dec + α (D_Dec – F_Dec )
D_Dec ⇒ 20 units
F_Dec = 25 units
F_Jan = 25 + 0.2 (20 – 25)
= 25 + 0.2 (–5) = 25 –1
F_Jan ⇒ 24 units

Correct Option: C

F_t+1 = F_t + α (D_t – F_t)
F_{Jan (2003)} = F_Dec + α (D_Dec – F_Dec )
D_Dec ⇒ 20 units
F_Dec = 25 units
F_Jan = 25 + 0.2 (20 – 25)
= 25 + 0.2 (–5) = 25 –1
F_Jan ⇒ 24 units

In an M/M/1 queuing system, the number of arrivals in an interval of length T is a Poisson random variable i.e. the probability of there being n arrivals in an interval of length T is
e^λT(λT)ⁿ The probability density function f(t) of the inter- arrival time is given by
n!

1. λ²(e^−λ2T)
1. e^−λ²T
  λ²
1. λ²e^−λt
1. e^−λT
  λ

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For any Poisson distribution, the probability density function f(t) is given by λe^{– λt} .

Correct Option: C

For any Poisson distribution, the probability density function f(t) is given by λe^{– λt} .