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1. Building Information System
Submitted to: Ms. Shaista Hussain
Submitted by:
Group No: 09
1: Nasir Aslam 2: M. Naveed
3: M. Shahzad 4: Saeed Ahmad Mari
DEPARTMENT OF COMPUTER SCIENCE & INFORMATION
TECHNOLOGY
The Islamia University of Bahawalpur

2. 1
Content list
System
Information
Information System
Strategic of Information System
Operational excellence
New products, services, and business models
Customer and supplier intimacy
Improved decision making
Competitive advantage
Survival
Approaches to auditing system development
Overview of system deployment
Participants in system deployment
Initiating system deployment
Information system planning
Aligning corporate and Is goals
Phases of any Information System
Initiation
Development
Implementation
Operation and maintenance
System deployment life cycle
Overview of the System Life Cycle
Information System Life Cycle process

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Feasibility study
System Investigation
System Analysis
System Design
Programing
Testing
System Testing
Acceptance Testing
Implementation
Review and maintenance
Phased Design and Implementation
Handling Change
Installation
Parallel
Direct
Phased
Pilot
The Mature System
Reevaluation
Advantages of Information System
Disadvantages of Information System
System.

4. 3
A system is a set of elements or components that interact with one an another to achieve a common goal.
Every person interacts with many systems during daily activities. A building system can be used by an
organization to send invoices and receive payment from customer. A payroll system is use to manage
employees’ salaries. A manufacturing system produced different goods for the customers. Similarly an
inventory system is use to manage the items in the stock.
Elements of system.
A system has three basic interacting components.
Input.
The data or instruction given to computer is called input.
Processing.
In this step data is convert into information by computer.
Output.
The data processed into is useful information is called output
Information.
“Data which is meaningful and useful for human beings.”
InformationSystem.
An Information system (IS) collect store and disseminate information from an organization enjoinment and
internal operation to sports organizational function, decision making, communication, coordination, control
and analysis and Realization.
Information system and technologies are a vital component of a successful business and organization. They
are considered a major functional area in business operation. They can improve decision making,
organizational performance and help to increase firm profitability. And information system supports daily,
short term and long-range activities of user in accompany.
Role of information system in business:
Three major role of information system in business are as follows;
1.Support Business process.
An information system supports different process and options in a business For example, most retail store
now use computer based information system This system provides the facility to store customer purchases,
manage the inventory, employers pay buy new products and evaluate sales trendsetc.

5. 4
2.Support decision making.
An information system helps the decision makers to make a better decision. It also supports the buyers and
others to gain an advantage over other retailers in the competition for customer.
3.Support competitive advantage.
An information system helps the decision makers to gain a strategic advantage over competitors gaining a
strategic advantage over competitors requires innovative application of information technologies For
Example The management of a store can make decision to install touch-screenkiosks in all stores with links
to their e-commerce website for online shopping This decision may attract new customer and build
customer loyalty’
Strategic of Information System:
Operational excellence.
o IS Improvement of efficiency of operation to attain higher profitability
o IT tool to achieve greater efficiency and productivity
o Example: Wal-Mart’s Retail Link system links suppliers to stores for superior replenishment system
New products servicesand business models:
o Business model: describes how company produces, delivers, and sells product or service to create
wealth
o Information systems and technology a major enabling tool for new products, services, business models
E.g. Apple’s iPod, iTunes and Netflix’s Internet-based DVD rentals
Customer and supplier intimacy:
o Serving customers well leads to customers returning, which raises revenues and profits E.g. High-end
hotels that use computers to track customer preferences and use to monitor and customize environment
o Intimacy with suppliers allows them to provide vital inputs, which lowers costs
E.g. J.C. Penney’s information system which links sales records to contract manufacturer
Improveddecisionmaking:
Without accurate information:
Managers must use forecasts,best guesses, luck Leads to Overproduction, underproduction of goods and
services Misallocation of resources Poor response times
o Poor outcomes raise costs, lose customers IS provide real-time data for making decisions

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E.g. Verizon’s Web-based digital dashboard to provide managers with real-time data on customer
complaints, network performance, line outages, etc.
Competitive advantage.
o Achieve higher sales and profit through using IS by:
 Doing things better
 Charging less for superior products
 real time Responding
 Using the internet is competitive advantage
 E.g. Dell: Consistent profitability over 25 years; Dell remains one of the most efficient producer of PCs
in world.
 But Dell has lost some of its advantages to fast followers-- HP
Survival.
Business firms also invest in information systems and technologies because they are necessities of doing
business. Sometimes these “necessities” are driven by industry-level changes. For instance, after Citibank
introduced the first automated teller machines (ATMs). Today,virtually all banks in the United States have
regional ATMs and link to national and international ATM networks, such as CIRRUS. Providing ATM
services to retail banking customers is simply a requirement of being in and surviving in the retail banking
business.
There are many federal and state statutes and regulations that create a legal duty for companies and their
employees to retain records, including digital records.
The Sarbanes— Oxley Act (2002), which was intended to improve the accountability of public firms and
their auditors, requires certified public accounting firms that audit public companies to retain audit working
papers and records, including all e-mails, for five years.
Many other pieces of federal and state legislation in health care,financial services,education, and privacy
protection impose significant information retention and reporting requirements on U.S. businesses. Firms
turn to information systems and technologies to provide the capability to respond to these challenge
Approaches to auditing system development:
Historically, a major debate among information system auditors has focused on the question of whether
they should become involved as a member of the project team during the system development process.
Those who favor involvement point out that errors are costlier to correct at latter stage in the system
development process. thus, auditor can play a valiances role by indicating where system development
deficiencies exist as an early stage. on the other hand, those who oppose involvement argue their
independence will be undermined if they must latter evaluate system they have helped design and
implement .They content that information system auditor should evaluate the system development process
only in an exposers review capacity.

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While eachof us might use a view use on merits of the respective argument .we must neverthelessthousand
both approaches to carrying out in audit of the system development process. The audit objectives and the
way to undertake evidence collection and evaluation will differ depending on the type of audit conducted.
When we participate in the system development process. we are seeking to ensure the development process
employed will lead to the production of a specific application system that safeguards assets. Maintain data
integrity and achieve system effectiveness and efficiency.
In the context of specific system to be developed. We must first from the view on how the system
development process should be undertaken next we collect evidence on the actual conduct of the system
development activities .our primary means of evidence collection is observation of the activities of the other
member of the system development team .in light of the evidence we collect we then advise the system
development team of any deficiencies we identify. when we conduction ex post audit of the system
development process ,we can have two objectives ,First we might be seeking to identify what went wrong
and what went right during the development of the specific system and perhaps and how the system should
be modified to better meet its objectives . over review is conducts after the system has been developed and
implemented and often after the system has been operational for some time, at the outset we consider the
nature of the system and organizational context in which it has been built and operated. we determine the
system development process we believe would have been best for the system. Next,we collect evidence on
how the system was actually developed so we can compare what occurred against our expectation. in light
of this comparison, we can generate hypotheses about the likely strength and weakness of the system we
then collect evidence to test our hypothesis.
We might also carry out an export audit, however for another reason. We might be hoping to reduce the
extent of substantive testing needed to established the basis for our audit opinion on the assertion
management makes about the financial statement or system effectiveness and efficiency the audit process
according to the overall approaches describe in previous chapter .First we use interviews, observations, and
a review of standard to obtain and understanding of system development control in general. Next, we
evaluate the level of control risk associated with system development control as a management control
subsystem. If we cannot access the control risk at the maximum level we then design an execute test to
evaluate whether the control on which we wish to rely are operating effectively. For example we might
select a sample of application system to determine weather system development personal I have complied
with design and testing standards.
In summary therefore, we might conduct Their type of audits of the system development process.
1.Concurrent audit: Auditor are members of the system development teams. They assist the team in
improving the quality of the systemdevelopment for the specific systemthey are building and implementing
(Gallegos 1988).
2.Post implementation audit: Auditors seek to help an organization learn from its experiences in the
development of specific application system. In addition, they might be evaluating whether the system need
to be scrapped, continued, or modified in some way.
General audit: Auditors evaluate system development control overall. They seek to determine whether they
can reduce the extent of substantive testing need to

8. 7
for audit opinion about management assertion relation to the financial statement or system effectiveness
and efficiency,
OVERVEIW OF SYSTEM DEVELOPMENT:
In today’s business, manager and implore in all functional areas work together and use business
information system as a result, user is helping with development and, many cases,leading the way. user
might request that a system development team determine whether they should push e few Pcs create an
attractive website.in other case, system development might involve purchasing or leasing an enterprise
resource planning (ERP).
The next provide with a deeperappreciate of the system development processand help you’re a while costly
failures. The united airline automated baggage system development project, for example, failed to deliver
baggage to airline passenger in good shape or on time. The $250 million system development project cost
united air line about $ 70 million to operate each year. according to Mr. McDonald, the airlines chief
operating officer” we have come to the conclusion that going to a manual approach is best.” Participant in
system development, such as Mr. McDonald, determine when a system development project file. they are
also critical to system development sources.
Participants insystemdevelopment:
Effective systemdevelopment requires a teameffort.The teamusually consist of stake holder, user,manger,
system development specialist, and various sport personal. This called the development team Is responsible
for determining the objective of the information system and delivering a system that meetsthese objectives,
many development team use a project manager to held the system development effort and the project
management approach to help coordinate the systemdevelopment process.A project is a planned collection
of activities that achieves a goal, such as constructing a new manufacturing plant or developing a new
decision support system. All project has defined a starting point and ending point, normally expressed as
dates such as august 4 and November 11. most have a budget, such as $150.000.
A project manager is responsible for coordinating all people and resource needed to complete a
project on time. In system development, the project manager can be an IS person is side the organization
or an external consultant hired to complete a project. project manager need technical, business, and people
skills. in addition to completing the project on time and within the specific time,
in the connect of system development, stakeholders are people who, either themselves or through the area
of organization they represent, ultimately benefit from the system development project. Users are people
who will interact with the system regularly. They can be employers, managers, or suppliers.

9. 8
Every development team should have a team leader. this person can be from the IS department, a manger
from the company, or a consultant from outside the company. The team leader need both technical and
people skills.
Initiating systems development:
System development initiatives arise from all levels of an organization and or both planned and unplanned.
the united states deployment of energy (DOE) and TECS yes development, for example, a system
development project to protect the electrical infrastructure of the united states. According to a consultant
for the system development project, “over goal her is to develop method to protect the critical of the U.S.
“the new DOE system will include software to monitor server,router, firewalls, and other components of
U.S.
Mergers and accretions can target many system development projects. When meet life acquired travels life
and annuity for $11 billion, when meet life vice president and chief information officer Steve shiniest had
to quickly combine IS operations. Every with similar information system, the procedure, culture, training
and management of the information system are often different requiring a realignment of the IS department.
the resulting loyalty program collect Information of its costumer to serve them better and provide customize

10. 9
service. Some believe the system development project could increase the revenue to the casino and
entertainment company by 100 of millions of $ annually.
`
The federal government also fosters new systems development projects in the private sectors.in the wake
of recent financial scandals, the government has instituted corporate financial reporting roles under the
submarines Oxley act.These regulations have causedmany U.S companies to initiate systems development
efforts. To comply with this law, companies can spend hundreds of thousands or millions dollars in new
system development efforts .many U.S companies or out sourcing their system development projects that
required Sarbanes-Oxley complies .some out sourcing companies in India or experiencing of 50 percent
growth in business as a result U.S public companies are expected to spend almost $6Billions per year to
comply with the Sarbanes Oxley law .newfederallegislation also created the organize retail theft task force
at the FBI. “the establishment of an FBI task force on organized retail theft is the major victory of retailer,”
said Joseph LaRocca,the national retail federations vice president for loss prevention.’’ this task for and
the related data base will play a major and putting these criminals where they belong- behind bars.’’
Information system planning and aligning corporate and IS goals:
Information systems planning and aligning corporate and IS goals are important are aspect of any system
development projects.
Desire to exploit new
opportunities, such as a new
e-commerce initiative
Increasing competition
Desire to make more
effective use of information
Organization growth
Merger or acquisition
Change in marketor external
environment
New laws or regulations
Perceptionof a problemor potential benefit
byindividual capable of initiated change
System development process
initiated
Problems with existing
system

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achieving a competitive advantage is often the overall objective of system development. general motors,
for example, decided to spend about $15 million to develop a better information system that will allow the
various GM subsidies and office around the world to operate asa more unified unit. GM hopes the improved
information systems will help it increased sales and profit in Africa, Asia, Latin America, middle east and
the united states.
Information systems planning and aligning corporate and IS goals are important are aspect of any system
development projects. achieving a competitive advantage is often the overall objective of system
development.
general motors, for example, decided to spend about $15 million to develop a better information system
that will allow the various GM subsidies and office around the world to operate as a more unified unit.
GM hopes the improved information systems will help it increased sales and profit in Africa, Asia, Latin
America, middle east and the united states.
Phases of any Information System:
change in purpose Statementof whatthe problemisand
scope,or schedule how the informationsystemshouldhelp
Realizationthatthe information programs that runs oncomputer
Systemmustbe change implement plus,userdocumentation
informationsysteminoperation
Realizationthatthe implementation as part of a businessprocess
Isincomplete
initiation
Implementa
tion
Developmen
t
Operation and
maintenance

12. 11
Initiation:
 1.the action of admitting someone into a secret or obscure society or group, typically with a ritual:
“rituals of initiation"
 Synonyms:
beginning,starting, commencement, institution, inauguration, ... moreantonyms:finish, expulsion
 2.the action of beginning something:
 “the initiation of criminal proceedings"
Initiation is the process of the defining the need to the change an existing worked system, identifying
the people who should be involved in deciding whatto do, and describing in generalterms who the work
system should operate differently and who any information system that support it should operate
differently. This phase may occur in response to recognized problems, such as data that cannot be found
and used effectively, or high error runs in data. In other causes,it is part of a planning process in which
is organization is searching for go bey ways to improve and innovate, even if current system post of no
overt problem. This phase concludes which a work system and information system should change, plus
a shared understanding that proposed changes are technically and organization feasible.
A key outcome of this phase is an understanding of a proposed information system’s purpose of goals.
Errors in this phase may result in information system that operate on the computer but don’t support the
organization’s goals. Because it is possible to change a system after it goes into operation, design errors in
the initiation phase may not be fatal to the project. however, they are especially expensive because the
subsequent effort in developing both the information system. Demonstrates the importance of identifying
design errors early in a system development process by showing how the cost of design errors escalates the
later they are discovered.
Some system project never goes beyond the initiation phase. For example, the analysis in this phase may
show that the likely benefits, or that the system is technically or organizationally impractical. Other system
efforts are abandoned because people cannot agree on system goals or because too few people in the
information system.

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Initiation development implementation operationand maintenance
The later a design error is detected,the more expensive it is to correct because so much rework and
retesting is required.
Organization care about the problem the system addresses,although no one wants to invest time and
effort in a project and then stop it, stopping a project at this phase is far better than pouring and effort into
something that will probably fail.
Additional.
The later that system changes are made in the SDLC, the more expensive these changes become.
Sometimes, information learned in particular phase requires cycling back to a previous phase.
In the systeminvestigation phase potential problems and opportunities are identified and considered in the
light of the goals of the business. System investigations attempt to answer the questions. What is the
problem and is it worth solving? The primary result of the this [[haze a denied development project for the
business problems or opportunity statements have been created.to which some organizational resources
have been committed and for which a system analysis is recommended. Systemanalysis attempts to answer
the question What must the process to identify the strengths, weakness, and opportunities for improvement.
The major customer of system analysis is a list of requirement and priorities. System design seeks the
questions “how will the information system do what is must do to obtained the problem. The primary
Result of the phase is the technical design that either describe type new describes how existing system
will be modified. The system design details system, input a duster interphase, specify hardware,software,
database,telecommunication, and procedure components and show how the components are related.
0
0.2
0.4
0.6
0.8
1
1.2
0 0.5 1 1.5 2 2.5 3
Y-Values

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Implementation involved the acquiring system component detail.
Sometimes, information learned in particular phase requires cycling back to a previous phase.
In the systeminvestigation phase potential problems and opportunities are identified and considered in the
light of the goals of the business. System investigations attempt to answer the questions. What is the
problem and is it worth solving? The primary result of the this [[haze a denied development project for the
business problems or opportunity statements have been created.to which some organizational resources
have been committed and for which a system analysis is recommended. Systemanalysis attempts to answer
the question What must the process to identify the strengths, weakness, and opportunities for improvement.
The major customer of system analysis is a list of requirement and priorities. System design seeks the
questions “how will the information system do whatis must do to obtained the problem. The primary Result
of the phase is the technical design that either describe type new describes how existing system will be
modified. The system design details system, input a duster interphase, specify hardware,software,database,
telecommunication, and procedure components and show how the components are related. Implementation
involved the acquiring system component detail.
Development:

15. 14
 1. The process of developing or being developed: “she traces the development of the novel"
 Synonyms : evolution, growth, maturation, expansion, enlargement,
 2. The process of starting to experience or suffer from an ailment or feeling:
 “the development of brittle bones"
3.Developing is the process of building or acquiring and configuring hardware, software, and other
resources needed to perform both the required IT-related functions and the required functions not related to
IT. This phase starts by deciding exactly how the computerized and manual parts of the work system will
operate. It then goes on to acquire the needed resources. If the hardware isn’t already in place, development
includes purchasing and installing the hardware. If the software isn’t in place, it includes purchasing the
software, producing it from the scratch,or modifying existing software. Regardless of how the hardware
and software are acquired,this phase includes creating documentation explaining how both the work system
and the information system are supposed to operate. The development phase concludes with thorough
testing of the entire information system to identify and correct misunderstandings and programming errors.
Completion of development does not mean “the system work.” Rather, it only means that the computerized
parts of the work system operate on a computer. Whether or not the “system works will be determined by
how it is actually used in the organization.
A key goal of the development phase is assuring that work system and information system features really
solve problems the users want solved. This is sometime difficult because many users are unable to describe
exactly how a better information system might help them. They also may not see that system modification
could help them in some ways but might become a hindrance in other ways. Another key goal is to perform
the technical work in a way that makes it easier to modify the information system as new need arise.
The rate of major difficulty and even out write project failure during the development phase is surprisingly
high. The previous chapter mentions a large survey in which only 16.2% of development projects work
completed within schedule and budget and produce all of the feature initially specify. Around 52.7% went
over budget, over the time estimate, on produce favor feature. And amazing 3.1% of the projects were
canceled before completion. In general, the larger and more complicated the project is, the more likely that

16. 15
it will encounter problems at this phase. Particular difficult are projects that require inputs from many
stakeholders in business situation in which new information and new priorities are engineering continually.
Project of this type often encounter a combination of unreasonable expectations insufficient resources,
technological risk, and inadequate project methodology and staff.
Some development failure also occurs due to insufficient specification and testing, a very visible example
of this type occurred in 1999 when $125 million spacecraft event to study the climate of Mars was lost
because it was off course by sixty miles after a sixteen million space mile journey from earth. Although the
full detail was still under investigation, it was now the jet Propulsion laboratory’s computer models for
calculating position and speed had been programmed using the metric system but that Lockheed. And
provided data on the rocket thrusters using the English system. The thrusters had been used over months
for making fine adjustment and no one had noticed the discrepancy until the Orbiter reached the vicinity of
Mars. Researchers hoping to gain important climate knowledge from data that would have been collected
were devastated by a system development error involving one of the most basic principles of high school
physics.”
Implementations:
Implementation is the carrying out, execution, or practice of a plan, a method, or any design, idea, model,
specification, standard or policy for doing something. As such, implementation is the action that must
follow any preliminary thinking in order for something to actually happen.
Implementation is the process of making a new or important work system operational of the organization.
the phase starts from the point when the software runs on the computer and has been tested .Activate the
implementation include planning user conversations to the new information system and work system ,and
work systemand folioing up to make source the entire system is operating effectively the .the implantations
face may involve a major change in the way of organization or individuals operator .conversion from old
of the new must be planed and execute carefully to private error or chaos I or information system that keep

17. 16
track of transaction s such as invoice and customer order the conversion process requires some users to do
double work politest operating simultaneously with the old and new systems and running information in
parallel helps identify unanticipated problem that min squire information system or work system
modification before implication is complete .
Political issue related to power and control within the organization often become possible during
implementation. For example, implementing an integrated sales and protection system might make
computerized production schedule data directly accesses to a sales department. Ideally, this data should
help sales and production work together. However, it might also permit sales to exert new pressure on
production which previously had sole access to the data. The new system cooperative rational might be
replaced with a win loss feeling. Such issues should be identified as early as possible.
Operationand Maintenance:
Operational maintenance is the care and minor maintenance of equipment using procedures that do not
require detailed technical knowledge of the equipment’s or system’s function and design. This category of
operational maintenance normally consists of inspecting, cleaning, servicing, preserving, lubricating, and
adjusting, as required. Such maintenance may also include minor parts replacement that does not require
the person performing the work to have highly technical skills or to perform internal alignment.
It is the ongoing operation of the work systemand the information system, plus effortsdirected atenhancing
either system and correcting bugs. At minimum, this requires that someone be in charge of insuring that the
work system is operating well. That the information system is providing the anticipated benefits, and that
the work system and information system will be modify again if the business situation calls for it.
People tend to overlook the significance of this phase. To till e IS staff, building now information systems
often seems more challenging and creative than keeping old ones effective as needs change, in fact, the
operation and maintainer cue phase is often challenging. For example, consider the response time and
uptime requirement of information system companies rely on for taking customer orders or managing

18. 17
factories. Once an information system is in operation, users expect it work. Downtime and bugs must be
dealt with immediately, which requires the ability to diagnose and correct problems under time pressure.
Stems Development Life Cycle:
The stems system development process is also called a systemdevelopment life cycle (SDLC) because the
activities associated in this process are ongoing. As each system is built, the project has timelines and
deadlines, until at the last the system is installed and accepted. The life of the system continues as it is
maintained and reviewed. if the system needs significant improvement beyond the scope of the main
organization. Chane significantly, a new project will be initiated and the cycle will start over. The fact of
the systemdevelopment is that the later in the SDLC anerror is detected.The more expensive it is to correct.
One the reason for the monitoring costsis that if an erroris occurredin alter phase of the SDLC the previous
phase us be reworked to some extent. A second reason is that error founds in SDLC affect more the people.
For example, an error in the system and after system is installed might require retraining users when a
workaround to the blew has been found. Thus, experiences system developers prefer an approach that will
be errors in early in the period life cycle.
Several common systems development life cycles exist rational prototyping, rapid applications
development (RAD) and end user development .in addition companies can outsource the process and

19. 18
development process.With some companies, these approachesare formalized and documents so that system
developers have a well-defined process to follow; in other companies, less formalized approaches are used.
Advantage:
1. Formal review is created at the end of each stage allowing maximum management control.
2. This approach creates considerable system documentation.
3. This documentation ensures that system requirements can be traced back to stated business
requirements.
4. It produces many intermediate products that can be reviewed to see whether they meet the user’s needs
and conform to standards. These can be further worked on if they require tweaks to be made, ensuring
that the business gets exactly what it needs.
5. Clear project objectives.
6. Stable project requirements.
7. Progress of system is measurable.
8. Strict sign-off requirements.
Disadvantage:
1. What may be seen as a major problem for some, end-user does not see the solution until the system is
almost complete.
2. Users get a system that meets the need as understood by the developers; this may not be what was
really needed for them. There may be a loss in translation.
3. Documentation is expensive and time-consuming to create. It is also difficult to keep current. What
may be current this month may not be the same this time next year!
4. Users cannot easily review intermediate products and evaluate whether a particular product (e.g., data
flow diagram) meets their business requirements.
5. Another disadvantage of a program or software that follows the SDLC program is it encourages stiff
implementation instead of creativity. There are requirements that must be met and that is all that
developers complete.
6. Time consuming
7. Never backward (Traditional)
8. Little room for iteration
9. Difficulty responding to changes
Overview of the System Life Cycle:

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New information systems are an outgrowth of a process of organizational problem solving. A new
information system is built as a solution to some type of problem or set of problems the organization
perceives it is facing.
The problem may be one in which managers and employees realize that the organization is not performing
as well as expected, or that the organization should take advantage of new opportunities to perform more
successfully.
The activities that go into producing an information system solution to an organizational problem or
opportunity are called systems development. Systems development is a structured kind of problem solved
with distinct activities. These activities consist of systems analysis, systems design, programming, testing,
conversion, and production and maintenance Figure illustrates the systems development process.
The systems development activities depicted usually take place in sequential order. But some of the
activities may need to be repeated or some may take place simultaneously, depending on the approach to
system building that is being employed
Information SystemLife Cycle process:
Information systems development life cycle (SDLC)
There are many variants it has the following basic structures.
*feasibility study
*system investigation

21. 20
*systems analysis
*systems design
*implementation
*review and maintenance.
These stages together are frequently referred to as conventional systems analysis traditional systems
analysis information systems development life cycle or more frequently in the USA, the waterfall model.
The term ‘life cycle’ indicates the staged nature of the process. Further by the time the review stage comes,
the information system may be found to be made equate and it may not be long before the process starts
again with a feasibility study to develop another information system to replace it. In the next few stations
we describe each stage in turn.
Feasibility study.
Among other reasons, a computer system might may be contemplated to replace an old system because
increasing workloads have overloaded the present system, suitable staff are expensive and difficult to
recruit, advancing technology leads to new possibilities, there is a change in the type of work, or there are
frequent errors. The next stage is to look in more detail at the present system and then to determine the
requirements of the new one.
The feasibility study looks at the present system, the requirements that it was intended to meet problems in
meeting these requirements, new requirements that have come to light since it was first implemented and
briefly investigates alternative solutions.
For each of these a description is given in terms of the technical human organizational and economic costs
and benefits of developing and operating the system. So any proposed system must be feasible.
*Legally, that is, it does not infringe any national or, if relevant, international company law.
*Organizationally and socially, that it is acceptable for the organization and its staff, particularly if it
involves major changes to the way in which the organization presently carries out its processing.
*Technically that it is, it can be supported by the technologically available and there is sufficient expertise
to build it.
*Economically, that is, it is financially affordable and the expense justifiable.
Of the possible alternatives, a ‘recommended solution’ is proposed with an outline functional specification.
This information is given to management as a formal report and often through an oral presentation by the
systems to management who will then decide whether to accept the recommendations of the analysis. This

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is one of the decision points in the SDLC whether proceed or not. of the possible alternatives a
recommended solution is proposed with an outline functional specification. This information is given to
management as a formal report and often although oral presentation by the system analysis to management
who will then decide whetherto acceptthe recommended by the system analysis. This is one of the decision
point in the SLDC. Whether to proceed or not.
Systems Investigation.
If the management is given to the approval to proceed, the next stages is detailed fact-finding phase. This
purpose the rough investigation of the application area. The information obtained will be much more
detailed than that recorded in the feasibility report. It will looks at.
*the functional requirements of the existing system and whether these requirements to be achieved.
*the requirement of the new systems there may be many situations or opportunities that augged altered
requirements.
*Any constraints imposed.
*the range of data type and volumes that have to be processed.
*exception conditions.
*problems of the present working methods.
These facts are gained by interviewing personnel (both management and operational staff) though the use
of questionaries’ by direct observation of the application area of the interest by sampling and by looking at
records and other written material related to the application area:
*observation can give a useful insight into the problems work conditions bottlenecks and methods of work.
*interviewing which may be conducted with individuals and groups of users is usually the most helpful
technique for establishing and verifying information and provides an opportunity to meet the users and to
start to overcome possible resistance to change:
System Analyses.
Armed with the facts the system precedes to the systems analysis phase and analysis the present system by
asking such questions as.
*Why do the problems exist?
*Why were certain methods of work adopted?
*Are there alternative methods?
*What are the likely growth rates of data?

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In other words, it is an attempt to understand all assets of present system and why it developed as it did.
And eventually indicate how things might be improved by the new system.
System Design.
Although usually modeled on the designs suggested the feasibility the studied phase. The new facts may
leads to the analyst adopting rather different designs to that purposed at that time. Much will depend on the
willingness to be through in the investigation phase and questioning in the analyst phase. The new design
might be similar to the previous system. But avoiding the problems that occurred with the old system and
without including and new ones. This stage involves the design of both computers and manual parts of the
system. The design documentation set will contain detail of:
*Input data and how the data is to be captured.
*Output of the system processed many carried out by the computer programs involved in the converting
the input to the output.
*Structure of the computer and manual files that might be referenced in the system.
*Security and backup provisions to be made.
*Systems testing and implementation plans.
Programing.
During the programming stage, system specifications that were prepared during the design stage are
translated into software program code. Today, many organizations no longer do their own programming
for new systems. Instead, they purchase the software that meets the requirements for a new system from
external sources such as software packages from a commercial software vendor, software services from an
application service provider, or outsourcing firms that develop custom application software fortheir clients.
Testing.
Exhaustive and thorough testing must be conducted to ascertain whether the system produces the right
results. Testing answers the question, “Will the system produce the desired results under known
conditions?” As Chapter 5 noted, some companies are starting to use cloud computing services for this
work. The amount of time needed to answer this question has been traditionally underrated in systems
project planning. Testing is time consuming: Test data must be carefully prepared, results reviewed, and
corrections made in the system. In some instances, parts of the system may have to be redesigned. The risks
resulting from glossing over this step are enormous.
Testing an information system canbe broken down into three types of activities: unit testing, system testing,
and acceptance testing. Unit testing, or program testing, consists of testing each program separately in the
system. It is widely believed that the purpose of such testing is to guarantee that programs are error-free,
but this goal is realistically impossible. Testing should be viewed instead as a means of locating errors in
programs, focusing on finding all the ways to make a program fail. Once they are pinpointed, problems can
be corrected. It is widely believed that the purpose of such testing is to guarantee that programs are error-
free,but this goal is realistically impossible. Testing should be viewed instead as a means of locating errors
in programs, focusing on finding all the ways to make a program fail. Once they are pinpointed, problems
can be corrected.

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SystemTesting.
System testing tests the functioning of the information system as a whole. It tries to determine whether
discrete modules will function together as planned and whether discrepancies exist between the way the
system actually works and the way it was conceived. Among the areas examined are performance time,
capacity for file storage and handling peak loads, recovery and restart capabilities, and manual procedures.
Acceptance Testing.
Acceptance testing provides the final certification that the systemis ready to be used in a production setting.
Systems tests are evaluated by users and the systems development team works with users to devise a
systematic test plan. The test plan includes all of the preparations for the series of tests we have just
described. Figure shows an example of a test plan. The general condition being tested is a record change.
The documentation consists of a seriesof test plan screensmaintained on a database (perhapsa PCdatabase)
that is ideally suited to this kind of application.
Implementation.
Following the system design phase is the various procedures that needs of the new system. If the design
includes computer programmers these have to be written and tested. New hardware and software system
needs to be purchased and installed if they are not available in the organization at present. It is important
that all aspects of the system are proven before cut over to the new system otherwise failure will cause a
lack of confidence in this and possibly future computer applications.
Alternatively, applications packages might be purchased to form part of the final system. In this approach
the analyses and programming function are separate tasks carried out by different people. A major aspect
of this phase is of that of quality control. The manual procedure along with the hardware and software
needed to be tested to the satisfaction of the users as well as analyzed. The users need to be comfortable
with the new methods. The education and training of user staff is therefore an important element of this
phase without through training users will be unfamiliar with the new systems and unlikely to cope with the
new approach.
Implementation.
Following the system design phase is the various procedures that needs of the new system. If the design
includes computer programmers these have to be written and tested. New hardware and software system
needs to be purchased and installed if they are not available in the organization at present. It is important
that all aspects of the system are proven before cut over to the new system otherwise failure will cause a
lack of confidence in this and possibly future computer applications.
Alternatively, applications packages might be purchased to form part of the final system. In this approach
the analyses and programming function are separate tasks carried out by different people. A major aspect
of this phase is of that of quality control. The manual procedure along with the hardware and software
needed to be tested to the satisfaction of the users as well as analyzed. The users need to be comfortable
with the new methods. The education and training of user staff is therefore an important element of this
phase without through training users will be unfamiliar with the new systems and unlikely to cope with the
new approach.

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Review and maintenance.
The final stage in the system development process occurs once the system is operational. There are beyond
to be some changes and some staff will be possible for maintenance which aims to insure the continued
clinical running of the system some of the changes will be due to changes in the organization of the
environment. Some to be technological advance in some to extras edit to the system at in agreed period
following operational running at some stage there will always be a review of the system to insure that it
does conform to the requirements set out at the feasibility study stage in the cost have not exceeded.
Phased Designand implementation.
Phased Design and implementation is a modified development scheme that mixes the detail design and
implementation stages. The philosophy underlying the phased approach might be explained as “design a
little, implement a little, then go back and design a little more.”
With the phased approach, implementation tends to follow quit quickly after a piece of the system is
designed the kind of problems that can be detected only during implementation will therefore be found
before incurring the cost of an entire detailed design. Typically, only the last little bit of design will need
to be changed, so changes, so changes tend to be less expensive.
Phased design and implementation also lets testing proceed in a more predictable manner. If a system small
enough or simple enough, the phased approach may not be needed. The phased approach addresses the
difficulty of building large systems reliably when we are at the frontiers of technology.
Handling Change.
The Design Freeze most businesses experience change in their operations and requirements every day, even
asa project is under way.When a change comes afterthe completion of a detailed design, it may be difficult
to adopt one approach to this problem is to have a design freeze, after which no changes are allowed until
the system is installed and working.
Installation.
During the installation stage the system is loaded on the production hardware and the database are
populated. Installation typically takes place during slow periods for the organization and if at all possible
while the system is not needed. If an existing is being replaced the firm migrates from the old one to the
new one following one from.
Parallel.
The old and new system are run for a time together. This approach is the most conservative as it offers
insurance against failure of the new application.
Direct.

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The old system is suddenly discontinued and the firm cuts over to the new one. This is most radical
approach.
Phased.
The new system progressively replaces the functionalities of the old one. This approach is best suited to
modular or componentized applications that can be rolled out in stages.
Pilot.
Well suited for multiunit operation this approach allows the firm to run the system in one business unit or
one of the firm is departments before rolling it out completely.
The Mature System:
Operation.
During operation the system is full use, this period is the mature phase of the life cycle.Although the system
is full use, neither the customer nor the developer realistically believes it will be totally free of problems,
Implementation and installation cannot test every possible combination of input, Some system fail in
Operation because this is their first opportunity to exercise their full capacity, for large loads and many
users are not easy to create in testing situation.
Maintenance.
Because there are errors even when the information system development is finished there will always be
maintenance which mean changes to working system. Maintenance of aninformation systemactually arises
from several sources:
1: error that were missed in the original implementation
2: performance improvements to keep up with increasing loads.
3: changes to the business environment such as new laws.
4: Enhancements to the function of the system to make it better serve the needs of the business.
Trouble Reporting.
When changesto a systemare expensive, userswho are having trouble may feeldiscouraged and not bother
reporting problems. Often, they find ingenious, but clumsy ways to work around them like bypassing the
computer entirely for certain types of transactions for which the system does not work.
If the users find a way around a problem, the system’s maintainers may not know that their system is not
working, so the problems may never be corrected,in that situation, the system operation soon become a
collection of undocumented ad hoc procedures.

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Reevaluation.
Asa business changes,the software will tend to change with it. Small changesto the software will generally
suffice for small changes to the business, but there are times when the business has changed sufficiently
that a price of software may seem too restrictive to meet its needs. At such times, the business can initiate
a reevaluation or system audit to determine the appropriate action, up to and including a complete
replacement of the old system.
The reevaluation can take the form of a small study or a large one In a few cases,the business has changed
so much, or the performance of the system is so far from original expectations, that the system is simply
put out of its misery. Termination is a difficult and rare decision, but it is always a possible outcome of a
reevaluation.
Advantages of Information System:
The advantages of IS are as follows:
 Information system can perform calculation much faster than people.
 They help companies to learn more about the purchase patterns and preference of their customer.
 They provide new efficiencies through improved processes and services.
 They distribute information quickly to the management for decision making.
 They provide new efficiencies through improved processes and services.
 They distribute information quickly to the management for decision making.
Disadvantages of Information System:
 Information system automate activities that were previously performed by people .it may result in
elimination of jobs.
 They allow organization to collect personal detail that may violate the privacy.
 They are used in every aspect of everyday life and organizations heavily rely on them. Any problem in
information system may cause shutdown of business. They allow organization to collect personal detail
that may violate the privacy.
 They are used in every aspect of everyday life and organizations heavily rely on them. Any problem in
information system may cause shutdown of business.