Investigating the utility of coupling COCOMO with a system dynamics simulation of software development.

184 Pages·3.5 MB·en_US

by  Smith, Richard W.;Abdel-Hamid, Tarek K.

NAVAL POSTGRADUATE SCHOOL
Monterey, California
THESIS
INVESTIGATINGTHE UTILITY OF COUPLING
COCOMO WITH A SYSTEM DYNAMICS
SIMULATION OF SOFTWARE DEVELOPMENT
by
RichardW. Smith
September, 1991
Thesis Advisor: Tarek K. Abdel-Hamid
Approved for public release; distribution is unlimited
T258624

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11 TITLE (IncludeSecurityClassification)
INVESTIGATINGTHEUTILITYOFCOUPLINGCOCOMOWITHASYSTEMDYNAMICSSIMULATIONOF
SOFTWAREDEVELOPMENT (UNCLASSIFIED)
12 PERSONALAUTHOR(S) Smith,RichardW.
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Master'sThesis From To September 1991 175
16 SUPPLEMENTARY NOTATION
TheviewsexpressedinthisthesisarethoseoftheauthoranddonotreflecttheofficialpolicyorpositionoftheDepartmentofDefenseortheLJ.S.
Government.
17 COSATICODES 18 SUBJECTTERMS(continueonreverseifnecessaryandidentifybyblocknumber)
FIELD GROUP SUBGROUP CostEstimation,SoftwareProjectManagement,SystemDynamicsSimulationModel,
COCOMO
19 ABSTRACT(continueonreverseifnecessaryandidentifybyblocknumber)
Costestimationofsoftware,inthiseraofbudgetaryconstraints,isvitallyimportanttothesuccessorfailureofasoftwareproject.
Althoughtherearemanycostestimationmodelsavailable,costoverrunsandlatedeliveriesstillpersist.
CouplingtheConstructiveCostModel(COCOMO)andtheSystemDynamicsModelofSoftwareProjectManagementcanprovide
atooltostudyprojectmanagementoverthelifeofaproject,tousesensitivityanalysistoenhanceCOCOMO'scostdriverset,andto
utilizeanautomatedoptimizationsystemforsoftwarecostestimationinasingleormulti-projectenvironment. Thisnewtypeofmodel
createsameanstostudythemulti-projectenvironmentanddeterminewhattheadvantagesanddisadvantagesaretosharingresources
betweendifferentsoftwareprojects.
Several'Cprogramsweredeve4oped,thatwheninterfacedandcoupledwiththesystemdynamicsmodel,provideatooltooptimize
costestimatesinatwoprojectenvironment. Italsocreatesanenvironmenttoperformextensivesensitivityanalysisfortheenhancement
ofCOCOMO'scostdriversetinthesingleandtwoprojectenvironment.
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TarekK.Abdel-Hamid [phone] AS/AH
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Approved for public release; distribution is unlimited.
COCOMO
Investigating the Utility of Coupling
with a System Dynamics
Simulation of Software Development
by
Richard W. Smith
Lieutenant, United States Navy
B.S., United States Naval Academy, 1982
Submitted in partial fulfillment
of the requirements for the degree of
MASTER OF SCIENCE IN INFORMATION SYSTEMS
from the
NAVAL POSTGRADUATE SCHOOL
September 199
)
Department of Adnrunistrative Sciences
u
ABSTRACT
Cost estimation of software, in this era ofbudgetary constraints, is vitally important
to the success or failure of a software project. Although there are many cost estimation
models available, cost overruns and late deliveries still persist.
Coupling theConstructiveCost Model (COCOMO) and the System Dynamics Model
of Software Project Management can provide a tool to study project management over the
life of a project, to use sensitivity analysis to enhance COCOMO's cost driver set, and to
utilize an automated optimization system for software cost estimation in a single or multi-
project environment. This new type of model creates a means to study the multi-project
environment and determine what the advantages and disadvantages are to sharing
resources between different software projects.
Several 'C programs were developed, that when interfaced and coupled with the
system dynamic model, provide a tool to optimize cost estimates in a two project
environment. It also creates an environment to perform extensive sensitivity analysis for
the enhancement ofCOCOMO's cost driver set in the single and two project environment.
ui
.
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TABLE OF CONTENTS
INTRODUCTION
I 1
A. BACKGROUND 1
B. OBJECTIVES 3
C. THE RESEARCH QUESTION 4
D. SCOPE 4
E. METHODOLOGY 4
F. ORGANIZATION OF STUDY 6
II. SYSTEM ARCHITECTURE 7
A. INTRODUCTION 7
B. A DYNAMIC SIMULATION MODEL OF SOFTWARE
DEVELOPMENT
7
C. COCOMO MODEL 11
D. INTERFACING "C" PROGRAMS WITH DYNAMIC SIMULATION
MODEL 14
1. SINGLE PROJECT ENVIRONMENT 18
2 TWO PROJECT ENVIRONMENT 22
.
III. SYSTEM OPERATION 28
A. BACKGROUND 28
B. SPECIAL FEATURES 28
C. GETTING STARTED 29
IV