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; The Effectiveness of
Management Information Systems
by
Eric F. Wolstenholme
University of Bradford
United Kingdom
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ABSTRACT
There are a large number of
references in the literature to the
problem of evaluating Information
Systems in terms of both efficiency
(the technical aspects) and
effectiveness (the users’ view, and
the effect the system has on the
organisation). Whereas efficiency
can be defined clearly in
mathematical terms, measurement of
effectiveness tends to be subjective
and is usually measured
retrospectively (i.e. some. time after —
installation) using: a- questionnaire
approach, or by expensive simulators,
prior to installation.
This presentation deals with the
initial thinking behind the
development of a quick and less
costly system dynamics approach to
measuring effectiveness, by using a
simple model to examine the effect
the proposed system will have on the
organisation into which it is to be
installed.
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PROBLEM
Present requirement analysis
techniques do not take into account
the influence a new information
system will, or can, have on
organisational structure and
policies, therefore, new information
systems often fail to meet
expectations.
REQUIREMENT
A technique which can be incorporated
into requirements analysis to allow
the analyst to model the
organisation, quickly and simply, in
terms of the interaction between the
flow of information and the
associated flow of goods/services
which the organisation produces.
ANSWER
A system dynamics model of a single
representative function using DYSMAP2
software on an IBM PC/AT or
compatible.
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METHODOLGY
STAGE 1 - The MANUAL system
Model a representative function of
the organisation in terms of its
physical and information flows, and
the policies which represent the
impact of one on the other.
STAGE 2 - The COMPUTERISED system
Modify the attributes of the
information flow (e.g. source,
accuracy, content, amount,
timeliness) to represent the effect
of the proposed information system.
STAGE 3 - The ENHANCED system
Use the model to investigate
modifications to policies and
structure which the proposed system
would facilitate, such that the full
potential of the system to improve
organisational performance is
realised.
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APPLICATION OF METHODOLOGY
TO DEMONSTRATION MODEL
ORGANISATION
Logistics operation with one main
depot supplying three distributors
(see figure). The demands of
Distributor 1 are seen to have
priority over those of Distributor 2
who, in turn, has priority over
Distributor 3.
The aim of the organisation is to
operate in such a way that each
distributor can satisfy as near to
100% of customer demand as possible.
STAGE 1
Models the distribution of one item,
in terms of the flow of that item
from depot store to the distributors,
the associated flow of information
and the policies (stock allocation,
transport allocation and resupply
policies) which affect these flows.
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DEMONSTRATION MODEL
ORDER DELIVERY +[ sTOck AT |g TOTAL
ae am MAIN DEPOT |* ae es
+hh =
vA \ DISTRIBUTOR 2
\
+ DISTRIBUTOR 3
PERCEIVED
ey STOCK AT aren
polic: A policy
ALLOCATED
5 SUEY RATE ISSEY RATE
a DISTRIBUTOR 1 DISTRIBUTOR 1
PERCEIVED
REQUIRED
SUPPLY. RATE +.
DISTRIBUTOR 1 DESPATCH
Ee ene
DISTRIBUTOR 1 policy
( |
exe! it” (A
DESPATCH
SUPPLY RATE RATE. TO CAPACITY
FOR DISTRIBUTOR 1 +
DISTRIBUTOR 1 X
DESIRED
STOCK AT D
DISTRIBUTOR 1
* RATE TO.
+
SUPPLY RATE ¢ DISTRIBUTOR 1
REQUIRED BY
DISTRIBUTOR a +e
STOCK HELD PROBABILITY
BY —, OF ARRIVAL
DISTRIBUTOR 1 OUTPUT ;
CUSTOMER ¢
DEMAND SS DISTRIBUTOR 1
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APPLICATION OF METHODOLOGY
TO DEMONSTRATION MODEL
STAGE 2
Models the effect of the proposed
installation of a computerised system
to give the inventory controller on-
line access to both transport
availability and the current stock
situation, such that stock will only
be released if sufficient transport
is available to deliver it.
STAGE 3A
Investigates the effect of a change
in transport management from a
priority to a proportional allocation
policy.
STAGE 3B
Investigates the additional effect of
a reduction in safety stock- Tholding
by the Distributors.
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TOTAL. NUMBER OF ITEMS ORDERED
BY MAIN DEPOT
qj
Me
100000--
80000;
60000;
SFE oO
40000;
SUFFICIENT
MODERATELY
000. 0.0.4,
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HELD AT MAIN DEPOT
MAXIMUM LEVEL OF STOCK
SPSS SONOS SSS
S552
a = CAPACITY
OF STORE
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VERY RESTRICTED
PERCENTAGE CUSTOMER DEMAND ACHIEVED
TRANSPORT CAPACITY
Spree SO
OO O090>"
SERRE
aweowze<onw awz<zZa
DISTRIBUTOR DISTRIBUTOR
2
a
OZPEMO MOFHAZMOWMV
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PERCENTAGE CUSTOMER DEMAND ACHIEVED
TRANSPORT CAPACITY
MODERATELY RESTRICTED
STAGE 1 STAGE SA STAGE $B
STAGE 2
oe
=
eo
=
T
6252
$5
K>
x
2
oS
O25
ws
mx
5%
$5
6,
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sean
tanita seneaterersomearoran eg
RSP Oo oOOPS Soe
5250552505255 SO
S25 SERRE
R22
C0Or SOS SEOCCOCOOOOOO OO.
525052 S62 revetereteretereteteteretenek.
auwecowze<ow awz<za
DISTRIBUTOR
a
@EM44
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MAXIMUM STOCK HELD BY DISTRIBUTORS
COMPARISON OF
STAGE 3 POLICIES ONLY
STAGE 3A STAGE $B
2600 ome somone es
1800
1000:
