CH1 Productivity
Labor
Productivity = Units produced/Labor-hours used
Multi-Factor
Productivity = Output / (Labor + Material + Energy + Capital + Miscellaneous)
% change = (new productivity – old productivity )/old productivity
CH2 Strategy
Weighted-point evaluation (factor-rating)
n
ScoreX =  PerformanceXY  WY
Y =1
where:
X = supplier X
Y = performance dimension Y
Performance XY = rated performance of supplier X with regard to performance dimension Y.
n
WY = assigned weight for performance dimension Y, where  WY = 1
Y =1
CH3 Project Management
forward
backward
Earliest Start Time Rule (ES) = Max {EF of all immediate predecessors}
Earliest Finish Time Rule (EF) = ES + Activity time
Latest Finish Time Rule (LF) = Min {LS of all immediate following activities}
Latest Start Time Rule (LS) = LF – Activity time
Slack = LS – ES
or
Slack = LF – EF
Crash cost per period = (Crash cost – Normal cost)/(Normal time – Crash time)
Expected time:
t = (a + 4m + b)/6
Variance of times:
v = [(b – a)/6]2
Due
date –
/sp
Estimate follows beta distribution
s2p = Project variance
= (variances of activities
on critical path)
Z=
Expected date
of completion
CH4 Forecasting (1 of 3)
Naive Approach
Exponential Smoothing
Ft +1 = Dt
Ft = Ft – 1 + a(At – 1 - Ft – 1)
where:
Ft +1 = forecast for the next period, t + 1
Ft :new forecast
Ft – 1 :previous period’s forecast
A
:smoothing (or weighting) constant (0 ≤ a ≤ 1)
At – 1 :previous period’s actual demand
and Dt = demand for the current period, t
Weighted
moving =
average
å(( Weight for period n) (Demand in period n))
å Weights
demand in previous n periods
å
Moving average =
n
CH4 Forecasting (2 of 3)
Least Square & Associative Forecasting
xy - nxy
å
b=
å x - nx
^
y = a + bx
2
a = y - bx
2
Standard Error of the Estimate
S y,x =
2
y
å - aå y - bå xy
Correlation
n-2
r=
nå xy - å xå y
2 ùé
2ù
é
2
2
êënå x - å x úûêënå y - å y úû
(
)
(
)
CH4 Forecasting (3 of 3)
Actual - Forecast
å
MAD =
Forecast Error = Actual - Forecast
n
(
MSE =
å Forecast errors
)
n
2
n
Tracking
Cumulative error =
=
signal
MAD
å100 Actual -Forecast / Actual
i
MAPE = i=1
i
i
n
å(Actual demand in period i -Forecast demand in period i)
å Actual-Forecast
n