Essay Questions
1.
Define and describe the relationship between methodology, technique,
and tool in terms of their
contributions to information systems development. Give examples of each of
these terms.
Answer:
Methodologies
are step-by-step approaches that help in the development of the final information
system. Methodologies are typically composed of a number of techniques, which
are processes that analysts follow to ensure that their work is well
thought-out, complete, and comprehensible. Techniques are facilitated through
the use of software tools. Examples of methodologies are the SDLC, structured
analysis, and object-oriented analysis. Techniques include interviewing and
direct observation for requirements analysis, planning and management
approaches to ensuring project success, and various diagrams for illustrating
system processes, data flows, and object relationships. The most commonly used
software tool for systems analysis is CASE (computer-aided software
engineering).
Page Reference: 4-5, 17-19 Difficulty: Moderate
2.
What is a system? Give a business-related definition and describe the
parts that make up a system.
Answer:
A
system in a business sense is a set of interrelated procedures used for a
business function with an identifiable boundary working together for some
common purpose. A system is made up of components linked with each other in
various relationships. Each component may be an irreducible part, or a
subsystem. Systems have constraints, which are limits on what they can do. A
system exists within an environment and is separated from the environment by a
boundary, and the points at which objects in the environment can interact with
the system are called interfaces; these are the points at which the system
receives its inputs and produces its outputs.
Page Reference: 5 Difficulty: Moderate
3.
Define the key systems analysis concepts of decomposition, modularity,
coupling, and cohesion. Why are these important concepts and how are they
related to each other?
Answer:
Decomposition
is the process of breaking a system into its terminal components and
subsystems. This produces modularity, which makes the system easier to
understand. A modular system is one in which the parts are small and
manageable, allowing designers and analysts to focus their attention without
being distracted by other modules. This also allows work on separate modules to
be done independently in terms of time and resources. Coupling refers to the
degree of dependence between modules. Ideally, coupling should be kept to a
minimum in order to maximize independence and interchangeability of system
units. Cohesion refers to the degree to which a system component performs a
single function. If a system component performs many functions, it should be
further decomposed so that its separate units are more cohesive.
Page Reference: 6-8 Difficulty: Moderate
4.
List and describe the steps involved in information systems
development.
Answer:
There
are four main steps in information systems development. These are project
management/planning, systems analysis, systems design, and systems
implementation/operation. In project planning, organizational needs are
identified, a feasibility study is performed, the scope of the proposed system
is determined, and a baseline plan is generated. Systems analysis involves a thorough
study of the current procedures and system operations, typically utilizing use
case analysis. In addition, system requirements are determined, and alternative
system designs are evaluated. The result of systems analysis is a clear
identification of what the system is supposed to accomplish. Systems design is
concerned with how the system will accomplish this. User interfaces, reports,
databases, and computer processes are fully described -- first in a logical
design and then in a physical design. Finally, in systems implementation,
program coding, testing, documentation and installation takes place. After this
point, the system is in operation, and requires periodic enhancement and
maintenance.
Page Reference: 9-11 Difficulty: Moderate
5.
Describe the three main categories of information systems. For each
category, indicate its primary purpose, discuss the types of inputs and outputs
that it uses, and give an example of an application of this type.
Answer:
The
three types of information systems are transaction processing systems (TPS),
management information systems (MIS) and decision support systems (DSS). A TPS
is an application that automates transaction processing, generally utilizing
raw data from databases and producing simple documents such as receipts or
invoices. A bank’s automated teller machine, a retail point-of-sale system, and
a company’s payroll system are all examples of transaction processing systems.
A management information system typically takes inputs from TPS data and
produces reports to managers that summarize and aggregate the transaction
activities. Regional sales reports and employee activity summaries are examples
of MISs. Whereas an MIS simply produces a static report, a DSS goes further by
providing an interactive environment that enables users to perform a variety of
decision-making tasks such as what-if analysis. DSSs obtain data from
databases, include mathematical and graphical models, and provide a dialogue
interface for users. Examples of DSSs are executive information systems (EISs),
data warehouses, and knowledge management systems.
Page Reference: 11-13 Difficulty: Moderate
6. Describe the main role of a systems analyst in
the systems development process. In a typical IS organization, who will the
systems analyst report to, and who does the systems analyst’s boss report to?
Finally, discuss several characteristics of successful systems development teams.
Answer:
The main role of
the systems analyst is to study the problems and needs of an organization in order
to determine how people, procedures, and information technology can best be combined
to bring about an improvement in the organization, typically by assisting
system users and managers in determining and structuring their requirements for
new or enhanced information services. The systems analyst typically reports to
the director of IS development,
who in turn reports to the executive director of the overall IS department. Successful development teams should be diverse, enabling a wide variety of viewpoints, backgrounds,
and expertise levels, which enables birth and development of new ideas. Successful teams are made up of people who are willing to consider ideas without being overly critical, who are able to deal with ambiguity, uncertainty and complexity, who are skilled technicians and communicators, and who are organized in a structure emphasizing mutual respect, trust,
and shared accountability.
who in turn reports to the executive director of the overall IS department. Successful development teams should be diverse, enabling a wide variety of viewpoints, backgrounds,
and expertise levels, which enables birth and development of new ideas. Successful teams are made up of people who are willing to consider ideas without being overly critical, who are able to deal with ambiguity, uncertainty and complexity, who are skilled technicians and communicators, and who are organized in a structure emphasizing mutual respect, trust,
and shared accountability.
Page Reference: 13-14
Difficulty:
Moderate
7. Identify and describe four types
of skills a person needs in order to succeed as a systems analyst. For each type of skill, indicate the tasks
and roles in which the analyst will utilize the skill.
Answer:
Systems
analysts utilize analytical, technical, managerial, and interpersonal skills in
their jobs. They use analytical skills to understand the organization and its
functions, to perform problem-solving tasks, and to identify opportunities and
problems. In particular, analytical skills facilitate system thinking, the
ability to identify organizations and programs and systems. Technical skills
are important in order to recognize which technologies are appropriate for
which problems, and to identify the strengths and limitations of each
technology. Among the technical skills required for a systems analyst are
database design, systems modeling, and programming. A systems analyst uses
management skills to assist or lead in project management efforts, manage
change, and minimize project risk. Finally, interpersonal and communication
skills are vital for the systems analyst, who serves as a liaison between users
and programmers, interviews users to obtain requirements, and participates in
meetings.
Page Reference: 15-16 Difficulty: Moderate
8. Identify and describe the
modeling and diagramming techniques that are used for the structured,
data-oriented, and object oriented analysis and design methodologies.
Answer:
The
structured analysis/design methodology focuses on process modeling, implemented
primarily via data flow diagrams (DFDs). Data flow diagrams illustrate the
movement of data between external entities, system processes and data stores.
DFDs can be shown at various levels of detail, as processes are decomposed into
sub-processes. The data-oriented methodology concentrates on data modeling,
particularly with respect to relational database technology. The primary
diagramming technique is the entity-relationship (ER) model. The
object-oriented methodology utilizes the unified modeling language (UML), which
is a notation that models business objects and software system artifacts.
Page Reference: 17-19 Difficulty: Moderate
9. Describe the advantages that the
object-oriented approach to systems analysis and design has over the
traditional systems development life cycle. In particular, discuss the
limitations of SDLC and how OOSAD overcomes these limitations.
Answer:
The
traditional SDLC places a heavy emphasis on planning and analysis early in the
process, forcing analysts to thoroughly understand the problem and construct
detailed development plans prior to designing and coding the system. Although
this can help to reduce errors during subsequent development efforts, its
sequential approach has several limitations. User requirements may not be known
in advance, and will probably change during the course of the development
effort, particularly for large projects.
Analysts often do not have enough functional knowledge to truly
understand user requirements and their implications for design. Furthermore,
project risk is not well-known early in the development process and does not
become apparent until later in the project, when significant resources have
already been expended. Because of the long time frame between project
initiation and final implementation, users do not get access to the system
until long after the project has begun, and by that time the system may no
longer meet their changing needs. Finally, the SDLC is generally associated
with a process-oriented structured analysis and design methodology, which
involves task decomposition and an inherent separation of processes and data.
By
contrast, the OOSAD approach emphasizes an incremental and iterative
methodology in which cycles of planning, analysis, design, and implementation
are spread throughout several phases of the project. At each phase, individual components of the
system are fully developed; therefore users gain access to pieces of the system
early in the process. Risk is mitigated because difficult tasks are tackled
early in the process, and the incremental approach is conducive to responding
to changing user requirements. In OOSAD, planning and analysis are an ongoing
process, so it is natural for an incomplete understanding of the system and
requirements to evolve into more detailed knowledge as the systems development
effort unfolds. Finally, because objects encapsulate both processes and data,
this leads to more support for reuse of components in different applications,
something generally not supported by applications developed via SDLC.
Page Reference: 17, 20-22 Difficulty: Hard
10. Describe in detail the Rational
Unified Process. Discuss the overall approach this methodology takes toward
systems development. Identify each of the phases, indicating the typical
subdivisions and describing which workflows that are emphasized in each.
Finally, discuss the relative lengths of each of the phases.
Answer:
The
RUP is an iterative, incremental approach to object-oriented systems analysis
and design. With this approach, the systems development process is divided into
four main phases, inception, elaboration, construction, and transition. Each
phase is subdivided into time-bound milestones called iterations, typically of
2-8 weeks each. Consider the traditional
SDLC in which almost all planning is done up front, followed by detailed
analysis, then logical and physical design, and finally implementation and
operations. With RUP, each phase consists of each of these “workflows” to some
degree, although they are emphasized in differing degrees in each phase. Management
and planning is distributed evenly across all phases. Analysis tasks are
heavily emphasized in the earlier stages (inception and elaboration) and are
reduced in emphasis in the later phases (construction and transition). Design
starts at a low level in inception, is dominant in elaboration, and then
gradually diminishes in construction and transition. Implementation slowly
builds in the early stages, and peaks in construction, then trails off in
transition. The operation workflow is at a minimal level in inception, slightly
higher in elaboration and construction, and peaks in transition. Inception is
usually the shortest phase, composed typically of a single iteration.
Elaboration is slightly longer, usually involving two iterations. Construction
is the most time and resource intensive, and may have several iterations, and
transition usually has only a couple iterations.
Page Reference: 22-25 Difficulty: Hard
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