Assignment
from Tri Djoko
Wahjono, Ir., M.Sc.
1.
What
Is System Development, and What Are the System Development Phases?
An information system (IS) is hardware,
software, data, people, and procedures that work together to produce quality
information.
System development is a set of activities used to build an
information system. System development activities often are grouped into larger
categories called phases.
This collection of
phases sometimes is called the system development life cycle (SDLC). Many SDLCs contain five phases: planning; analysis; design; implementation; and operation, support,
and security.
2.
What
Are Guidelines for System Development? System development should follow three general guidelines:
(1) group activities
into phases;
(2) involve the users, which includes anyone for whom a system is being built; and
(3) define standards, which are sets of rules and procedures an organization expects employees
to accept and follow.
3.
Why
Are Project Management, Feasibility Assessment, Documentation, and Data and
Information Gathering Techniques Important?
Project management is the process of planning, scheduling, and
then controlling the activities during system development. The goal of project management
is to deliver an acceptable system to the user in an agreed-upon time frame,
while maintaining costs.
For larger projects, project
management activities often are separated between a project manager and a project leader.
Some organizations use extreme project management. The project leader identifi es the scope of the project, required activities, time estimates, cost estimates,
the order of activities, and activities that can take place simultaneously. The
project leader records this information in a project plan.
Feasibility is a measure of how suitable the development
of a system will be to the organization.
A systems analyst typically uses four tests to evaluate
feasibility of a project: operational
feasibility, which measures how
well the proposed system will work; schedule feasibility, which measures whether established project deadlines are
reasonable; technical feasibility, which measures whether the organization has
or can obtain the hardware, software, and people to deliver and then support
the system; and economic feasibility, also called cost/benefit feasibility, which measures whether the lifetime benefits
of the proposed system will be greater than its lifetime costs.
Documentation is the collection and summarization of data
and information and includes reports, diagrams, programs, or other
deliverables.
A project notebook contains all documentation for a single
project. To gather data and information, systems analysts and other IT
professionals review documentation, observe, survey, interview, participate in joint-application design ( JAD) sessions, and
research.
4.
What
Activities Are Performed in the Planning Phase?
The planning phase for a project begins when the
decision-making body for the organization, called the steering committee, receives a project request. During the planning phase, four major
activities are performed:
(1) review and approve
the project requests,
(2) prioritizethe
project requests,
(3) allocate resources
such as money, people, and equipment to approved projects, and
(4) form a project
development team for each approved project.
5.
What
Is the Purpose of Activities Performed in the Analysis Phase?
The analysis phase consists of two major activities:
(1) conduct a preliminary investigation, sometimes called the feasibility study, to determine the exact nature of the
problem or improvement and decide whether it is worth pursuing, and (2) perform
detailed analysis.
Detailed analysis involves three major activities:
(1)
study how the current system works;
(2)
determine the users’ wants, needs, and requirements; and
(3)
recommend a solution. Detailed analysis sometimes is called logical design.
Most
systems analysts use either a process modeling or object modeling approach to
analysis and design.
6.
What
Are Tools Used in Process Modeling?
Process modeling, sometimes called structured analysis and design, is an analysis and design technique that
describes processes that transform inputs into outputs. Tools used for process
modeling include the following.
An entity-relationship diagram (ERD) graphically shows the
connections among entities in a system. An entity is an object in the
system that has data.
A data flow diagram (DFD) graphically shows the
flow of data in a system. Key elements of a DFD are a data flow, which shows the input or output of data or information; a process, which transforms an input data flow into an output data flow; a data store, which is a holding place for data and
information; and a source, which identifies an entity outside the
scope of the system. The project
dictionary, sometimes called the repository, contains all the documentation and
deliverables of a project. Techniques used to enter items in the project
dictionary include structured English, a decision table and/or a decision tree, and a data dictionary.
7.
What
Are Tools Used in Object Modeling?
Object modeling, sometimes called object-oriented (OO) analysis and design, combines the data with processes that act
on the data into a single unit, called an object. Object modeling can
use the same tools as those used in process modeling, but the UML (Unified Modeling Language) has been adopted as a standard notation
for object modeling and development. Two common tools in the UML are the use
case diagram and the class diagram.
A use case diagram graphically shows how actors interact with
the information system. An actor
is a user or other
entity, and the use case is the function that the actor can perform.
A class diagram graphically shows classes and one or more
lower levels, called subclasses, in a system. Lower levels (subclasses)
contain attributes of higher levels (classes) in a concept called inheritance.
8.
What
Activities Are Performed in the Design Phase?
The design phase consists of two major activities:
(1) if necessary,
acquire hardware and software and
(2)
develop all of the details of the new or modified information system. Acquiring
necessary hardware and software
involves identifying technical specifications, soliciting vendor proposals, testing and evaluating vendor
proposals, and making a decision. Detaileddesign includes developing designs for the databases, inputs,
outputs, and programs. During detailed design, many
systems analysts use a prototype, which is a working model of the proposed
system. Computer-aidedsoftware engineering (CASE) products are tools designed to support one
or more activities of system
development.
9.
Why
Is Program Development Part of System Development?
During the design
phase, an organization can purchase packaged software, which is mass-produced, copyrighted, prewritten software. If suitable
packaged software is not available, however, a company may opt for custom software, which is application software developed at
the user’s request to match the user’s requirements exactly. Programmers write
custom software from the program specifi cation package created during the
analysis phase, following an organized set of activities known as the program development life cycle.
10. What Activities Are Performed in the
Implementation Phase?
The purpose of the implementation phase is to construct, or build, the new or modifi
ed system and then deliver it to the users. System developers perform four
major activities in this phase: (1) develop programs,
(2) install and test
the new system,
(3) trainusers, and
(4) convert to the new
system.
11. What Activities Are Performed in the
Operations, Support, and Security Phase?
The purpose of the operation, support, and security phase is to provide ongoing assistance for an
information system and its users after the system is implemented. The
operations, support, and security phase consists of three major activities:
(1) perform maintenance
activities,
(2) monitor system
performance, and
(3) assess system security.
Organizations today often have a chief security officer (CSO) who is responsible for physical security of
an organization’s property and people and also is in charge of securing
computing resources. The CSO develops a computer security plan, which sum marizes in writing all safeguards that protect the
organization’s information assets.
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