A
Available to Promise (ATP) for period 1: on hand – customer order due before next MPS
Available to Promise (ATP) for period 2: MPS scheduled receipt – customer orders due before next MPS
Average inventory = order quantity/2 + safety stock = (starting inventory + ending inventory)/2
Average inventory in transit = (transit time in days) * (annual demand)/365
B
Backlog = total forecast + opening backlog – ending backlog or
Backlog = previous backlog + input – output
Bias = cumulative actual demand – cumulative forecast
C
Carrying cost = capital (not product cost) + storage + risk costs
Critical ratio = actual time remaining / lead time remaining
D
Days of supply = inventory on hand / average daily usage
Deseasonalized demand = actual seasonal demand/seasonal index
E
Economic Order Quantity Where
A Annual Usage in units; S Ordering cost in $; i Annual inventory carrying cost as decimal; C unit cost
Exponential smoothing = α * latest demand + (1 – α) * previous forecast; α is smoothing constant
Efficiency = standard hours of work/hours actually worked * 100%
F
G
Gross margin = revenue – cost of goods sold
Gross profit = revenue – cost of products sold
H
I
Inventory turns = annual cost of goods sold/average inventory in dollars
J
K
L
M
Manufacturing Lead Time = Queue time + Setup time + Run time + Wait time + Move time
Mean Absolute Deviation MAD – sum of absolute deviations (actuals – forecast)/number of observations
N
Net income = gross margin – general and administrative expenses
Net requirements = gross requirements – scheduled receipts – available inventory
O
Order point = demand during lead time + safety stock
Order quantity = target inventory – on hand quantity
Order time = setup time + run time
Owner’s equity= assets – liabilities
P
Period-order quantity = EOQ/average weekly usage
Projected Available Balance (PAB) before demand time fence = prior period PAB or on-hand balance + MPS – customer orders
Projected Available Balance (PAB) after demand time fence = prior period PAB + MPS – greater of customer orders or forecast
Process Capability indexCp= (Upper limit – lower limit)/6 sigma
whenCp> 1 process is capable; if Cp< 1 process is not capable; when Cp> 2 then we have a Six Sigma process (3,4 defects per million pieces)
Q
R
Rated capacity = available hours * efficiency * utilization
S
Seasonal index = period average demand/average demand for all periods (deseasonalized demand)
Standard Deviation Sigma ; n number of observations
T
Target inventory = delivery lead time demand + periodic review duration demand + safety stock
Tracking signal = sum of forecasting errors/Mean Absolute Deviation
U
Utilization = hours actually worked/available hours * 100%
V
W
X
Y
Z