Operations Management Formula Sheet Essay Example
1. EVPI = Expected value with perfect information – Maximum EMV = EVwPI – Maximum EMV
2. Moving Average
[pic]
3. Weighted Moving Average
[pic]
4. Exponential Smoothing
[pic]
5. Linear Regression
[pic]
6. MAD and Tracking Signal(TS)
[pic]
7. EOQ [pic] Q*=Optimal number of units per order (EOQ) Q = Number of units per order D = Annual Demand, Units H = Holding (or Carrying) Cost, $ / unit /year S = Ordering (or Setup) Cost, $ / order or setup P = Price per unit
Total Cost = [pic]
8. EOQ (Production order quantity model):
[pic] Total Cost = [pic] Imax = [pic] p = Daily production rate d = Daily demand rate, or usage rate
9. REORDER POINT: (Fixed Order Quantity Model)
I. Demand varies, Lead time constant
ROP = (Average daily demand * Lead time in days) + Z[pic]
II. Lead time varies, Demand constant
ROP = (Daily demand * Average lead time in days) + Z(Daily demand) * [pic]
III. Both Demand and Lead time vary
ROP = (Average daily demand * Average lead time) + Z[pic]
Where [pic]= Standard deviation of demand per day [pic] [pic]= Standard Deviation of lead time in days Z = Number of standard deviations
10. ORDER QUANTITY: (Fixed Time Period Model)
[pic]
11. Single period inventory model
Service level = [pic] where [pic]= Cost of Shortage = Sale price/unit – Cost/unit [pic]= Cost of Overage = Cost/unit – Salvage value/unit
12. Process Control Using Attribute Measurements
[pic]
where [pic]=mean fraction defective in the samples z = number of standard deviations [pic]= standard deviation of the sampling distribution
13. Process Control by Variables
[pic]
Where
[pic]=mean of the sample means [pic]=average range of the samples [pic] = values from the chart below
Factors for
2. Moving Average
[pic]
3. Weighted Moving Average
[pic]
4. Exponential Smoothing
[pic]
5. Linear Regression
[pic]
6. MAD and Tracking Signal(TS)
[pic]
7. EOQ [pic] Q*=Optimal number of units per order (EOQ) Q = Number of units per order D = Annual Demand, Units H = Holding (or Carrying) Cost, $ / unit /year S = Ordering (or Setup) Cost, $ / order or setup P = Price per unit
Total Cost = [pic]
8. EOQ (Production order quantity model):
[pic] Total Cost = [pic] Imax = [pic] p = Daily production rate d = Daily demand rate, or usage rate
9. REORDER POINT: (Fixed Order Quantity Model)
I. Demand varies, Lead time constant
ROP = (Average daily demand * Lead time in days) + Z[pic]
II. Lead time varies, Demand constant
ROP = (Daily demand * Average lead time in days) + Z(Daily demand) * [pic]
III. Both Demand and Lead time vary
ROP = (Average daily demand * Average lead time) + Z[pic]
Where [pic]= Standard deviation of demand per day [pic] [pic]= Standard Deviation of lead time in days Z = Number of standard deviations
10. ORDER QUANTITY: (Fixed Time Period Model)
[pic]
11. Single period inventory model
Service level = [pic] where [pic]= Cost of Shortage = Sale price/unit – Cost/unit [pic]= Cost of Overage = Cost/unit – Salvage value/unit
12. Process Control Using Attribute Measurements
[pic]
where [pic]=mean fraction defective in the samples z = number of standard deviations [pic]= standard deviation of the sampling distribution
13. Process Control by Variables
[pic]
Where
[pic]=mean of the sample means [pic]=average range of the samples [pic] = values from the chart below
Factors for