1242.2219 Information System Economics The Concept of Balance.
-
Upload
christian-jordan -
Category
Documents
-
view
218 -
download
0
Transcript of 1242.2219 Information System Economics The Concept of Balance.
1242.2219
Information System Economics
The Concept of Balance
The Concept of Balance
The problem – multiple dimensions:
computer: processor
printer
disks
CDROM
modem
software
personnel
Why is it needed?
The Concept of Balance
Kiviat Charts
Origin and history
The Concept of Balance
Kiviat Charts - The Method
1. Choose factors to be measured
2. Define factors so that for half the optimum utilization is 1
and for half 0
3. Mark of the factors around the chart so that axes with an
optimum of 0 alternate with those with an optimum of 1.
4. Mark of the values on the factor axes
5. Join the marks to form a “star”
6. Evaluate the result
The Concept of Balance
A 0.8B 0.2C 0.8D 0.2E 0.8F 0.2G 0.8H 0.2
Kiviat charts - a perfectly balanced system
0
0.2
0.4
0.6
0.8
1A
B
C
D
E
F
G
H
Series1
The Concept of Balance
00.20.40.60.8
1A
B
C
D
E
F
G
H
Series1
A 0.9B 0.15C 0.85D 0.2E 0.9F 0.1G 0.8H 0.2
Kiviat charts - a well-balanced system
The Concept of Balance
A 0.4B 0.6C 0.5D 0.4E 0.7F 0.4G 0.6H 0.5
0
0.2
0.4
0.6
0.8
1A
B
C
D
E
F
G
H
Series1
Kiviat Charts – a poorly balanced system
The Concept of Balance
A 1B 0C 1D 0E 1F 0G 1H 0
0
0.2
0.4
0.6
0.8
1
A
B
C
D
E
F
G
H
Series1
Kiviat Charts – a perfectly balanced system
The Concept of Balance
Kiviat Charts – a different exampleComparing Internet diffusion in countries
Measures: pervasivenessgeographic dispersionsectoral absorptionconnectivity infrastructureorganizational infrastructuresophistication of use
Countries compared:FinlandJordanIsrael
Dimension Jordan Israel Finland
Pervasiveness 3 4 4
Geographic Dispersion 1 4 3
Sectoral Absorption 2 3 3
Connectivity Infrasructure 1 2 3
Organizational Infrastructure 2 4 4
Sophistication of Use 1 3 4
Internet Dimensions Compared
0
1
2
3
4Pervasiveness
GeographicDispersion
Sectoral Absorption
ConnectivityInfrasructure
OrganizationalInfrastructure
Sophistication of Use
Internet Dimensions Compared
Jordan Israel Finland
The problem with Kiviat Charts - how to develop a metric for multidimensional data?
The solution: express everything in terms of a common measure - cost.
There are then two dimensions - utilization and cost - which, when multiplied yield a cost/utilization factor for each system component.
The Cost/Utilization Method
1 2 3 4 6
0 20 40 60 80 100
100
80
60
40
20
0
Percent of Cost
Per
cent
age
Util
izat
ion
Illustrative Cost/Utilization Histograms
Totalcost
1 2 3 4 6
0 20 40 60 80 100
100
80
60
40
20
0
Percent of Cost
Per
cent
age
Util
izat
ion
Illustrative Cost/Utilization HistogramsGood balance - high utilization - bottleneck
Totalcost
1 2 3 4 6
0 20 40 60 80 100
100
80
60
40
20
0
Percent of Cost
Per
cent
age
Util
izat
ion
Illustrative Cost/Utilization HistogramsGood balance - high utilization - bottlenecks
1 2 3 4 6
0 20 40 60 80 100
100
80
60
40
20
0
Percent of Cost
Per
cent
age
Util
izat
ion
Illustrative Cost/Utilization HistogramsGood balance - low utilization
1 2 3 4 6
0 20 40 60 80 100
100
80
60
40
20
0
Percent of Cost
Per
cent
age
Util
izat
ion
Illustrative Cost/Utilization HistogramsPoor balance - low utilization
1 2 3 4 6
0 20 40 60 80 100
100
80
60
40
20
0
Percent of Cost
Per
cent
age
Util
izat
ion
Illustrative Cost/Utilization HistogramsGood balance - high utilization - bottleneck
The Concept of Balance
Cost/Utilization - The Method
1. Choose factors to be measured
2. Determine the cost of each factor as a percent of total
system cost
3. Determine the utilization of each factor
4. Prepare a chart showing the cost and utilization of each
factor
5. Compute the measure of cost/utilization, F
6. Compute the measure of balance, B
7. Evaluate the resulting chart and measures
The Concept of Balance
Cost/Utilization - The Measures
Cost/utilization:
where: ui = percent utilization of factor i
pi = cost contribution of factor i
Balance:
F = iu lpi
∑
( ) ii puFB *2
21 −−=
The Concept of Balance
Cost/Utilization - The Measures
F=(0.3*0.5)+(0.6*.3)+(0.5*0.2) = 0.43
F
0.5 0.3 0.2
0 0.5 1.0
0.5
1.0
The Concept of Balance
Cost/Utilization - The Measures
F
0.5 0.3 0.2
0 0.5 1.0
0.5
1.0 B =1−2 .3−.43( )2 *.5+ .6−.43( )
2 *.3+ .5−.43( )2 *.3( )
≈1−2* .136=.728
The Concept of Balance
Cost/Utilization - Interpretation
F
0.5 0.3 0.2
0 0.5 1.0
0.5
1.0
processor disk I/O
The Concept of Balance
Cost/Utilization - Interpretation
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Series1 Series2 Series3
processor
printer
F = .42B = .53
disk 2disk 1
I/Os
The Concept of Balance
Cost/Utilization - Interpretation
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Series1 Series2 Series3
hardware
S/Wdevelopment
telecom
F = .42B = .53
personnelS/Wmaintenance
Trace of Cost/Utilization Criteriau
pPeriod 1: F=0.460, B=0.912
u
Period 2: F=0.496, B=0.908p
u
pPeriod 3: F=0.535, B=0.934
u
pPeriod 4: F=0.578, B=0.890 Period 5: F=0.627, B=0.816 Period 4: F=0.683, B=0.720
u u
p p
Composite cost/utilization histogram for two real linked systems
CP
U I
Mem
ory
I
CP
U I
I
Mem
ory
II
Dis
ks
Tap
es
Pri
nter
Car
d re
ader
F=0.488B=0.580
The Concept of Balance
Conclusions
It is essential to maintain balance between system components in order to:
reduce costs
maintain smooth functioning with no bottlenecks
attain effectiveness AND efficiency