How an Information System is Developed?

How an Information System is Developed 1

How an Information System is Developed

BS IT(MOR) GROUP NO 10 Presented

ByM.Junaid Mushtaq (1047)

Ayesha Sumara (1048)M. Majeed (1050)Anum noor (1045)Tahir khan (1049)

Manzoor farid (1046)

Submitted To

Inam Ul-Haq

University of Education, Okara Campus


Outline

• Objectives• Overview • The Need for Structured Systems Development • System Development Process: • Methodologies

Waterfall Process: • Evaluation criteria • Options for Obtaining Information Systems• The Need for Structured • life cycle of an information system from

conception to retirement • Approaches to Designing and Building Systems • Reference



Objectives Understand the process of IS managementUnderstand the system development life cycle

(SDLC)Understand alternative approaches to system

developmentUnderstand in-house system developmentUnderstand external acquisition, outsourcing,

and end-user development


Overview of system development:

The Need for Structured Systems Development

Systems analysis and design – the process of designing, building, and maintaining information systems

The individual who performs this task is called Systems analystOrganization wants to hire System analyst because they have both technical and managerial expertise.


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System Development Process Two Forms of System Development Process

(Waterfall & Iterative)

Outline:of The Need for Structured Systems Development


System Development ProcessOrganizational goals & plansOrg. processes and data As-is vs. To-beSystem solutions to problems in org. processes &

dataResult of IS Analysis & Design are system

requirements*Programming, purchasing software & hardware;

also called “implementation”Reality checkFine-tuning the system


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System Development Methodologies:Waterfall Process:

System development steps can be run on the entire system sequentially in defined periods. This is Waterfall methodology.

Linear, no turning back to previous step. Inflexible: once defined system requirements are fixed. If development time longer, system may be obsolete at time

Evaluation criteria:Strategic alignment: The extent to which the project is viewed as helping the organization achieve its strategic objectives an d long-term goal.

Potential benefits: The extent to which the project is viewed as improving profits, customer service, and the duration of the benefits


Potential costs and resource availability: The number and types of resources the project requires and their availabilityProject size / duration: The number of individuals and the length of time needed to complete the projectaTechnical difficulty / risks: The level of technical difficulty involved to complete the project within a given time and resources

Evolution of IS development

• The term 'information systems' tends to be associated with organisationally-based computing, perhaps with a slightly more systemic focus than the related term 'information technology'. David Avison (1995) writes: "whereas 'Information Technology' (to my mind) emphasises the technological aspects of computing, 'Information Systems' does not suggest that any one aspect subsumes others. ... However, I realise that many [IFIP] WG 8.2 members who have similar interests to my own, regard this wider area as being 'Information technology'. And that 'Information Systems' represent only the formal and engineering aspects."

How an Information System is Developed9

Research conducted under the banner of IS/IT generally tends to derive from management schools rather than computing departments, but also from departments of informatics, where that term is in use. Evaluations of IT in broad ways have also been carried out by sociologists (e.g Webster, 1990) and people from other social sciences. While this work has often been influenced by the programme evaluation literature (see section 2.3), it also often reproduces similar results and conclusions independently. Once again, there is a considerable body of work, which I shall only summarise in the briefest of ways here.

• Farbey (1995:207-8) writes that the purposes of IT evaluation are typically: as a basis for decision-making, control or accountability; legitimisation of a decision already taken, for example on strategic grounds; to gain and retain committment from stakeholders; as a learning process for the organisation and its members; and as a starting point for negotiation and collective decision-making.

• A familiar strain from this area is the need to consider the organisational context of use, and to take into account many perspectives - calls which are also heard elsewhere in this report. Neils Bj¿rn-Andersen writes: "much of our Information Systems research has failed to consider the dynamic nature of our environment and the demands placed on society and individuals" (1984:1). Similarly, Peter Checkland argues that "uniformity of perspective cannot be imposed upon autonomous human beings" (1984:17).


• mBy contrast, Targett (1995:203) writes that "evaluation has too narrowed an interpretation in many organisations, being taken to refer to the quantification of well-defined benefits with the sole objective of getting the project over organisational fences". Likewise, Blackler and Brown (1985:1) write "whilst social and organisational factors may be crucial for the successful implementation of [IT], most evaluation models fail to emphasis or even to include such factors" while Farbey et al (1994:44) write that "in practice few managers feel comfortable with anything other than Return on Investment (ROI) calculations, supplemented by a verbal description of the 'soft' or 'intangible' benefits“

• From “art” to a “discipline”: In the early days of computing it was considered an art that a very few people could master

Standardized development methods: The techniques used to build an IS varies greatly from individual to individual. It was very difficult to integrate and maintain. To address this problem, info. Sys. professionals decided to use a disciplined approach of introducing common methods, techniques, and tools for building information systemsSoftware engineering: This evolution led to the use of the term software engineering to define what system analyst & programmer do.


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OPTIONS FOR OBTAINING INFORMATION SYSTEMS

1. Build your own2. Buy a prepackaged system from a software

development company or consulting firm. Example: Payroll system.

3. Outsource development to a 3rd party: outside organization custom build a system to an

organization’s specifications. Good option when an organization does not have adequate resources or

expertise.

End user development: Individual users and departments build their own custom systems to

support their individuals. Example MS. Excel


The Need for Structured


The Need for Structured Systems Development

System Construction ProcessIdentify a large IT problem to solve Break the large problem into several smaller, more

manageable piecesTranslate each “piece” (small problem) into computer

programsPiece together each program into an overall comprehensive

IS that solves the problem The Role of Users in the Systems Development

ProcessIt is important for all members of the organization to

understand what is meant by system development and what activities occur.

Effective partnership: A close and mutually respectful working relationship between analysts and users is a key to project success.


Steps in the Systems Development Process


Systems Development Life Cycle (SDLC) Systems development life-cycle:

Model of the systems development life cycle, highlighting the maintenance phase.The systems development life cycle (SDLC), also referred to as the application development life-cycle, is a term used in systems engineering, information systemsand software engineering to describe a process for planning, creating, testing, and deploying an information system.[1] The systems development life-cycle concept applies to a range of hardware and software configurations, as a system can be composed of hardware only, software only, or a combination of both.[2]

http://en.wikipedia.org/wiki/Systems_development_life-cycle#cite_note-1

http://en.wikipedia.org/wiki/Systems_development_life-cycle#cite_note-2

http://en.wikipedia.org/wiki/File:SDLC-Maintenance-Highlighted.png


Describes the life cycle of an information system from conception to retirement.

System identification, selection, and planning System analysis System design System implementation

System maintenancePhase 1: System Identification, Selection, and Planning

Undertake only those projects critical to mission, goals, and objectives

Select a development project from all possible projects that could be performed

Different evaluation criteria used to rank potential projects

http://en.wikipedia.org/wiki/File:SDLC-Maintenance-Highlighted.png


Evaluation criteriaStrategic alignment: The extent to which the project is viewed as helping the organization achieve its strategic objectives an d long-term goal. Potential benefits: The extent to which the project is viewed as improving profits, customer service, and the duration of the benefitsPotential costs and resource availability: The number and types of resources the project requires and their availabilityProject size / duration: The number of individuals and the length of time needed to complete the projectTechnical difficulty / risks: The level of technical difficulty involved to complete the project within a given time and resources

Phase 2: System AnalysisCollecting System Requirements: Requirement collection is process of gathering and organizing information from users, managers, business processes, an documents to understand how a proposed system should work

System analysts use a variety of techniques to collect system requirements

Interviews: analysts interview peopleQuestionnaires: analysts design and administer surveys.Observations: analysts observe workers at selected timesDocument analysis: analysts study business documents

Critical Success Factors (CSF): analysts ask each person to define her own personal CSFs.Joint Application Design (JAD): Special type of a group meeting where all users and analysts meet at the same time


Phase 3: System Design• Designing forms and reports• Designing interfaces and dialogues• Designing databases and files• Designing processing and logic


Phase 4: System ImplementationSoftware programmingSoftware testing

Developmental: Programmers test the correctness of individual modules and the integration of multiple modules Alpha: Software tester tests whether it meets design specificationsBeta: Actual system users test the capability of the system in the user environment with actual data

System conversionParallelDirectPhasedPilot

System documentation, training, and supportUser and reference guidesTraining and tutorialsInstallation procedures and troubleshooting guides


Phase 5: System Maintenanceo Maintenance process steps:• Obtain maintenance request• Transform requests into changes• Design changes• Implement changes

o Maintenance types:• Corrective maintenance• Adaptive maintenance• Perfective maintenance• Preventive maintenance


Other Approaches to Designing and Building Systems

• Prototyping• Rapid Application Development (RAD)

• Object-Oriented Analysis & Design (OOA&D)• Need for Alternatives to Building Systems Yourself• Limited IS staff• IS staff has limited skill set• IS staff is overworked• Problems with performance of IS staff


Reference • Prepared by Kevin C. Dittman forSystems Analysis & Design Methods 4edby J. L. Whitten & L. D. Bentley• http://rohan.sdsu.edu/faculty/rnor

man• Jump up^ Blanchard, B. S., &

Fabrycky, W. J.(2006) Systems engineering and analysis (4th ed.) New Jersey: Prentice Hall. p.31

http://rohan.sdsu.edu/faculty/rnorman

http://rohan.sdsu.edu/faculty/rnorman

How an Information System is Developed?

Education

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