WCU The System of West Coast University Medical Center Was a Failure Case Study

Chapter 2
Systems Approach
Project Management for Engineering,
Business, and Technology
Prepared by
John Nicholas, Ph.D.
Loyola University Chicago
Definition of System
A system is an organized or complex whole; a
group of parts interacting in a coordinated
way.
1. The parts of the system affect the system
and are affected by it
2. The group of parts does something
3. The group is of particular interest. What you
define as the system depends on your
purpose.
System Concepts and Principles
Goals and Objectives
◼ Human-made systems are designed to do
something; they have goals and objectives
that are conceived by people.
◼
In designing a human-made system, the
place to start is by defining the goal of the
system and a hierarchy of objectives that
relate to the aspects the system.
System Concepts and Principles
Elements and Subsystems
◼
Systems can be broken down into smaller parts.
◼
These parts in combination form “the assemblage of
parts” that constitutes the system.
◼
The smallest part of a system is an element.
◼
The parts of the system might themselves also be
systems; these are called subsystems.
A subsystem is a system that functions as a component or
part of a larger system.
A Company as a System
The “whole” system
Company
Management
Personnel
Marketing
Production
Finance
Research and
Development
Functional subsystems
Production
manager
Scheduling
Production subsystem
Manufacturing
Manufacturing
subsystem
Team A
Supervisor
Team B
Inventory
Elements
System Concepts and Principles
Attributes
◼ Systems, subsystems, and elements each have
distinguishing characteristics called attributes
◼
These describe or express the condition of system,
subsystem, or element in qualitative or quantitative
terms.
◼
In human-made systems, many of the attributes are
designed into the system so that the system
performs as required.
System Concepts and Principles
Environment and Boundary
◼
The environment refers to anything that influences
the behavior or outcome of the system, yet lies
beyond the decision maker’s or stakeholder’s ability
to control
◼
The system is separated from its environment by a
boundary. The boundary might be somewhat
obscure, and it might be difficult to distinguish the
system from its environment.
System Concepts and Principles
To distinguish the system from its environment
ask two questions:
Is it relevant to the system?
Can the decision maker
control it?
Yes
No
Yes
System
No
Environment
The Irrelevant
Environment
System Concepts and Principles
System Structure
◼
Elements and subsystems are linked together
by relationships. The form of the relationships
is referred to as the structure of the system.
◼
Most systems, including projects, can be
conceptualized as hierarchical and network
systems.
Hierarchical structure
X
A
a
B
b
c
d
C
e
f
g
Network structure
e
d
c
b
a
g
f
Two ways of conceptualizing a project
System Concepts and Principles
Inputs, Process, Outputs, Interfaces
◼ Human-made systems achieve objectives by converting
inputs into outputs through a defined process.
◼
Outputs: end-result of a system and the purpose for which
the system exists.
◼
Inputs: the raw materials, resources, or prior steps
necessary for the system to operate, produce outputs, and
meet objectives.
❑
Feedback: Input that originates from the system itself.
System Concepts and Principles
Inputs, Process, Outputs, Interfaces (Cont’d)
◼
Process: means by which the system transforms inputs
into outputs.
❑ One goal of system design is to create a process that
produces the desired outputs and meets system
objectives effectively, and minimizes consumption of
inputs and production of wasteful outputs.
◼
Where the output of one element becomes the inputs of
the other, they are said to interface.
Input-process-output relationship
Inputs
Process
Feedback
Outputs
System Concepts and Principles
Constraints and Conflicts
◼ Systems constraints are limitations that inhibit the
ability of a system to reach goals and objectives. Time
and money are two universal constraints.
◼ In human-made systems, the objectives of the
subsystems sometimes conflict with each other, which
reduces the ability for them or the overall system to
realize their objectives.
◼ Removing
conflict between the objectives of
subsystems to enable the overall system to meet its
objectives is called integration.
System Concepts and Principles
System Integration
◼ For a system to perform effectively and achieve its
goal, all of its elements must work in unison.
◼
Designing, implementing, and operating a system to
achieve pre-specified objectives and requirements
through the coordinated functioning of its elements
and subsystems is called system integration.
System Concepts and Principles
Open Systems and Closed Systems
◼ A closed system is one that is viewed as selfcontained; “closed-systems thinking” means to focus
on the operation, structure, and processes of a
system without regard to the environment.
◼
An open system interacts with and adapts to its
environment.
◼
Any system that must be adaptable to its
environment must be treated as an open system.
◼
Human organizations and social systems are open
systems.
System Concepts and Principles
Natural versus Human-Made Systems
◼
Natural systems came into being by natural
processes (e.g., animal organisms and planetary
systems).
◼
Human-made systems are designed and operated
by people (e.g., communication systems and human
organizations).
◼
Projects exist for the purpose of creating or
enhancing human-made systems (or altering natural
systems).
Systems Approach
The systems approach
◼ Acknowledges that the behavior of any one
element affects the behavior of others and
that no single element can perform effectively
without help from the others.
◼
Recognizes interdependencies and causeeffect relationships among elements.
Systems Approach (cont’d)
◼
Retains attention on the overall system and
the ultimate goal
❑
◼
Allows focus on the parts, but only in regard to
their contribution to the whole system
Avoids actions that focus exclusively on parts
of the system, since such actions are
suboptimal for the total system.
Systems Approach Methodology
An Orderly Way of Appraisal
The systems approach is a methodology for solving
problems and managing systems that accounts for
1. The objectives and the performance criteria of the
system.
2. The environment and constraints of the system.
3. The resources of the system.
4. The elements of the system, their functions,
attributes, and performance measures.
5. The interaction among the elements.
6. The management of the system.
The methodology commonly employs models
System Models
◼
◼
A model is a simplified representation of the world; it
abstracts the essential features of the system under
study.
A physical model is a scaled-down abstraction of the
real system. It includes some aspects of the system
and excludes others.
❑
◼
Example: model airplane.
A conceptual model depicts the elements, structure,
and flows in a system in terms of a schematic
diagram or mathematical formulation.
❑
Example: population dynamics schematic (next)
Conceptual model of population dynamics
Deaths
Initial age
group
aging
Intermediate
age group
Births
Migration
aging
Terminal
age group
System Life Cycle
◼
All living organisms follow life-cycle stages
ConceptionC
Nonliving systems life cycle
• Conception
• Design
• Fabrication
• Installation
• burn-in
• Operation
• Deterioration
• or obsolescence
• Decommission
Birth
Growth
Maturity
Decline
Death
Systems Engineering
◼
◼
◼
The science of designing complex systems in their
totality to insure that the components and
subsystems making up the system are designed,
fitted together, checked, and operated in the most
efficient way.
The conception, design, and development of
complex systems where the components themselves
must be designed, developed, and integrated
together.
A way to bring a whole system into being and to
account for its whole life cycle—including operation
and phase-out—during its early conception and
design.
Dimensions of Systems Engineering
1
3
2
Dimensions of Systems Engineering (Cont’d)
1. SE is a multifunctional, interdisciplinary,
concurrent effort.
❑
❑
Systems engineers work with the system’s
stakeholders to determine their needs and what
the system must do to fulfill them.
The needs become the basis for defining the
system requirements, which specify what the
system will do.
Dimensions of Systems Engineering (Cont’d)
It addresses the system’s structure and
elements—its functional and physical
design.
2.
❑
❑
System elements and subsystems are designed
to perform the functions necessary to satisfy
stakeholder objectives and requirements.
The design effort focuses on how the system will
meet the requirements.
Dimensions of Systems Engineering (Cont’d)
It takes into account the way the system will
be produced, operated, maintained, and
finally disposed of—the entire system life
cycle.
3.
❑
This helps insure that the system will be
economical to develop, build, operate, and
maintain, and friendly to users and the
environment.
Systems Engineering Process
Forsberg and Mooz’s V-model (adopted from K. Forsberg and H. Mooz in Software Requirements Engineering, 2nd
ed., ed. R. Taylor, M. Dorfman, and A. Davis (Los Alamitos, Calif.: IEEE Computer Society Press, 1997): 44-77).
Systems Engineering Process (cont’d)
Creating a system concept that will satisfy
requirements involves a series of steps to
define the subsystems and elements of the
system. The process is an iterative cycle of
1)
2)
3)
top-down analysis of details (decomposing the
system into smaller parts)
bottom-up synthesis (building up and integrating
the parts into successively larger parts)
evaluation (checking to see that results meet
requirements)
Systems Engineering Process (cont’d)
The downstroke of the V represents
subdividing functions of the system into
subfunctions and requirements.
◼
❑
At each level the process of working with
customers to define requirements repeats, except
the “customer” becomes the function at the next
higher level and the question becomes, What must
the functions at this level do to meet the
requirements of the next higher level function?
Systems Engineering Process (cont’d)
◼
❑
❑
❑
❑
◼
◼
❑
❑
The upstroke of the V represents
assessing “design alternatives” to satisfy requirements
implementing design decisions—converting designs
into physical parts
integrating the parts
verifying that the integrated parts meet the
requirements.
The alternatives involve procuring available parts or
designing and building new ones.
Parts are checked individually and then assembled into
modules and again tested.
If tests reveal that parts or modules do not meet
requirements, the process returns to the downstroke of
the V to determine why.
the analysis-synthesis-evaluation cycle repeats.
Project Management is a Systems
Approach
◼
◼
It is total-system oriented
It emphasizes achievement of the overall
mission and objectives of the project
❑
◼
It optimizes the overall project rather than the
elements or subsystems of the project
It recognizes interaction and synergy among
elements of the project
❑
Outputs from one element provide inputs to other
elements.
Project Management is a Systems
Approach (Cont’d)
◼
It recognizes interactions and interdependencies between project elements and with the
environment
❑
Organizations, responsibilities, knowledge, and
data are integrated toward achieving overall
project objectives.