Project Engineering: Computer-Oriented Planning and Operational Decision Making

245 Pages·1990·8.7 MB·English

by  Anastasia Pagnoni (auth.)

Pagnoni Project Engineering
Anastasia Pagnoni
Project Engineering
Computer-Oriented Planning
and Operational Decision Making
With 102 Figures
Springer-Verlag
Berlin Heidelberg New York London Paris
Tokyo Hong Kong Barcelona
Anastasia Pagnoni
University of Modena
Department of Pure and Applied Mathematics
Via Campi, 2131b, I -41100 Modena, Italy
Present address:
University of Milan
Department of Computer Science
Via Moretto da Brescia, 9, 1-20133 Milano, Italy
ISBN-13: 978-3-642-75632-0 e-ISBN-13: 978-3-642-75630-6
DOl: 10.1007/978-3-642-75630-6
Library of Congress Cataloging-in-Publication Data
Pagnoni, Anastasia
Project engineering: computer-oriented planning and operational decision making!
Anastasia Pagnoni.
p.em.
Includes bibliographical references and index.
1. Engineering -Management. 2. Decision-making. I. Title.
TA194.P34 1990 90-10039 658.4'04 - dc20
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© Springer-Verlag Berlin Heidelberg 1990
Softcover reprint of the 1s t edition 1990
The use of registered names, trademarks, etc. in this publication does not imply, even in the
absence of a specific statement, that such names are exempt from the relevant protective laws
and regulations and therefore free for general use.
2145/3140(3011)-543210 -Printed on acid-free paper
To Elena and Francesco,
my marvellous kids
Preface
Project engineering is the discipline concerned with the application of science to the life
cycle of those complex phenomena we call projects.
Very often coordinated human activity is conceived as a project and executed to
achieve projected goals. This holds true in every field of human activity: there are manu
facturing and building projects, engineering and research projects, organizational and po
litical projects.
In everyday language -and in this book -the word project is used to indicate a past,
ongoing, or future planned effort, driven by a definite interest, and usually involving a
number of people and activities: planned effort for building a house, running a manufac
turing process or a scientific experiment, perfonning a specific unit of research, or orga
nizing a school system.
Project engineering encompasses a multitude of methodologies, and its practice re
quires familiarity with different techniques and a critical understanding of diverse ap
proaches.
This book offers a unitary presentation of several quite different planning lTlethod
ologies. Unavoidably, the selection - graphs, activity networks, CPM, PERT, GERT,
condition/event nets, place/transition nets, predicate/transition nets - reflects the au
thor's view of project planning. But I am convinced that this choice offers a solid plat
fonn for developing and analyzing project plans. In addition, the book introduces op
erational decision making, a methodology - based on the theory of fuzzy sets - for
supporting plan execution supervisors in making operational decisions. The methodolo
gies presented arose partly in the field of computer science and partly in the field of op-
VIII Preface
erations research. All of them are here introduced and discussed with the idea that com
puter tools can be acquired or developed to support planning, analysis and supervision of
projects.
I have written this book as a basic introduction to project engineering. I have sought
as well to supply an efficient project engineering toolbox, and to offer a unifying intro
duction to a wide cross-section of the relevant questions and results in the area. Particular
care has been devoted to providing practical guidelines on when each of the techniques
may be appropriately used. The appendix "Further Reading" will help the reader pursue
particular topics in greater depth.
The book is dedicated to professionals and practitioners, but it may well be used as
complementary textbook for a graduate level course in system engineering, control engi
neering, computer aided planning, decision support systems, or operations research.
The subject matter is expounded in a self-contained fashion, though the reader is
supposed to possess the mathematical background of a graduate level computer science
student.
Acknowledgements
Some features of this book which the author particularly likes were helpful suggestions of
Dr. Anatol Holt. Without his thorough reading of the manuscript, the book would have
been poorer in content and less pleasant in form. Our lively discussions made writing this
book a challenging experience.
A particular acknowledgement to Prof. Luigi Pojaga for revising the exposition of
networking techniques with competence and friendly care. Thanks also to Mr. J. Andrew
Ross of Springer-Verlag for correcting the English and suggesting substantial improve
ments of the manuscript.
A special "grazie!" to Dr. Hans Wossner and Mrs. Ingeborg Mayer for their
encouraging support and effective advice.
Finally, the author would like to mention her debt to Prof. Giovanni Degli Antoni for
having started her in the field of Computer Science, and sustained her ever since.
Milan, January 1990 Anastasia C. Pagnoni
Contents
v
Preface
Contents VII
Mathematical Notations XI
Introduction 1
1. Survey of Methodologies 5
2. Planning with Temporal Constraints 35
2.1 Graphs, Weighted Graphs, Bipartite Graphs 35
Subgraphs 38
Digraphs 38
Walks in Graphs and Digraphs 41
Connected Graphs, Weakly and Strongly Connected Digraphs 41
Trees 42
Graph Matrices 43
Digraph Representation of Plans 43
2.2 Activity Networks 44
Planning with Activity Networks 45
Activity Network Unfoldings 49
3. Disciplined Planning 51
3.1 Top-Down Development of Plans 52
3.2 Disciplined Planning Syntax 58
X Contents
4. Planning under PrecedencelDuration Constraints: Networking Techniques 65
4.1 No Choices, No Cycles, Known Durations: CPM 66
Execution Control: Event Time Bounds 67
Critical Paths 69
Event Realization Slacks 70
Activity Time Bounds 73
4.2 No Choices, No Cycles, Known Direct Costs: Cost-CPM 75
Updating of Time Schedule and Cost Plan 78
Cost Optimization 81
Analytical Cost Optimization Algorithm 82
A Heuristic Speeding Up Algorithm 83
Operational Considerations 85
4.3 No Choices, No Cycles, Beta-Distributed Durations: PERT 87
Probability Distribution of Activity Durations 88
The Beta Distribution 88
The Critical Path Question 93
Investigation of Project Completion Time 94
Warnings about Improper Use of PERT 97
PERT Cost Planning and Optimization 101
Operational Considerations 102
4.4 Choices, Cycles, Random Durations: GERT 103
Event Realization "Logics" 103
Network Structure 107
Probability Distribution of Activity Durations 108
STEOR Networks and Markov Renewal Processes 110
The MRP Method 112
Simulation of GERT Networks 117
5 . Clock-Independent Planning: Petri Nets 119
5.1 Causal Interconnection of State and Transition Elements: Nets 121
Enabling, Steps, Reachability 124
Pure Nets, Simple Nets 126
S-Graph, T-Graph, Free Choice Net 126
Subnets, S-Vectors, T-Vectors 128
5.2 Causal Interconnection of Conditions and Events: CE Nets 129
About Petri Net Plans 133
Contents XI
5.3 Causal Interconnection of Resources and Operations: PT Nets 134
Incidence Matrix 139
Reachability Graph 141
Liveness, Stop States and Home States 143
5.4 Conservation of Resource Counts and Reproduction of States:
S-and T-Invariants 145
Calculation of Invariants 149
Project Analysis by Means of Invariants 153
5.5 Representing Operations with Variable Resources Compactly:
an Outline ofPrT Nets 156
6. Net Plan Executions 163
6.1 Representing Net Plan Executions 164
Execution Nets 165
6.2 Figuring Out Execution Alternatives: Control Nets 170
7. Choosing a Course of Action: Operational Decision Making 185
7.1 Execution Alternatives 186
7.2 The Formal Representation of Vagueness: Fuzzy Sets 186
7.3 Fuzzy Attributes 188
Attributes over Operations 189
Attributes over Alternatives 190
Attributes over Executions 191
7.4 Preference Degree of Executions. Optimal Executions 198
Weighted Attributes 200
7.5 Clustering Executions into Preference Classes: Fuzzy Outranking 207
Fuzzy Outranking Relation 208
Classification of Executions 216
Singling out Best Executions: Dichotomy 216
Partitioning Executions into Preference Gasses: Polychotomy 217
References 219
Further Reading 221
Index 227
Mathematical Notations
Sets are denoted by upper case letters, set elements by lower case letters. Vector and
matrix identifiers are bold-face, and so are identifiers of relations, graphs, and nets. The
following notations are frequently used in the book:
equal to
'# different from
E belongs to
e does not belong to
:l comprehends
:::> strictly comprehends
.....
{ } set
0 empty set
J?(X) the power set of X
n intersection of subsets
U union of subsets
\ set difference
x set product
v or
1\ and
-, not
~X~ the cardinality of set X
M(X) the set of multisets over set X