4/8: Systems Analysis & Development Systems change affecting organizations Systems development Influences on & challenges to implementation Systems development.

4/8: Systems Analysis & Development

• Systems change affecting organizations

• Systems development

• Influences on & challenges to implementation

• Systems development approaches

• Systems building methodologies

Systems development & org. change

automation

rationalization

reengineering

paradigm shift

RIS

K

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automation

Systems development & org. change• Automation

– Using the computer to speed up the performance of existing tasks

RETURN

Systems development & org. change

rationalization

• Rationalization– Involves streamlining of standard operating

procedures, eliminating obvious bottlenecks, so that automation makes operating procedures more efficient.

Systems development & org. change

reengineering

• Reengineering– Radical redesign of business processes, combining &

eliminating steps to reduce waste and repetition, to improve cost, quality, and service.

– Management must understand & measure current design to assess improvements with new design.

Systems development & org. change

paradigmshift

• Paradigm shift– Rethinking the nature of the business and the nature

of the organization itself.

2 Ways to Find the IS Requirements• Enterprise Analysis: “looking at the whole”

– Central approach: ask large number of managers:• How they use information, where they get it• What their environments are like• What their objectives are• How they make decisions• What their data needs are

– Create logical application groups:• Groups of data elements that support related sets of

organizational processes.

– Tends to automate whatever exists, no fundamental change.

2 Ways to Find the IS Requirements• Strategic Analysis, or CSF: Critical Success

Factors– CSFs shaped by industry, environment, and manager– Central approach: 3-4 personal interviews with top

management, identify goals and the CSFs.– Advantages

• smaller data set to analyze.• Takes into account the environment & industry.

– Disadvantages: • it’s an art form• opinions may differ on what the CSFs are• Biased toward top management

Systems Development• All activities that produce an IS solution to an

organizational problem or opportunity.

• A structured kind of problem-solving with six distinct activities:– Systems analysis– Systems design– Programming– Testing – Conversion– Production & Maintenance

Systems Analysis• Defining the problem

• Identifying its causes

• Specifying the solution

• Identifying the information requirements needed.

Systems Analysis• Includes a feasibility study

– Technical feasibility• Is the proposed solution technically achievable? Is it

possible?

– Economic feasibility• Do the benefits outweigh the costs?

– Operational feasibility• Will it work in the organizational & managerial

framework?

• Do an organizational impact analysis:– How a new IS will affect org. structure, attitudes, decision-

making, and operations.

Systems Analysis: Info Requirements• Basically: who needs what information, when,

where, and how?

• Incredibly important!

Systems Design• Detailed how a systems will met the information

requirements as determined by the systems analysis.

• Like a blueprint of a house

• Logical design– Lays out IS components and their relationships as

they would appear TO USERS.– Shows what the proposed IS is supposed to DO.

• Physical design– Specs out the hardware, sofware, databases, etc.

Programming & Testing• Programming: System specifications created in

the design phase are translated into program code.

• Testing: vital step, often shortchanged.– Unit testing: seeking errors in particular programs– System testing: does the whole thing work together?– Acceptance testing: evaluation by real users, review

by management.

Conversion• Putting the new IS into production

• Parallel strategy:– run both old & new simultaneously.

• Direct cutover:– Old completely replaced by new on spec. day.

• Pilot study:– Limited implementation by small group of users.

• Phased approach:– Parts of new IS are introduced separately.

Production & Maintenance• New IS is up and running: in production.

• At this point, changes in the IS are called “maintenance”.

• Changes made are usually to improve efficiency.

Influences on & Challenges to Systems Implementation

• User involvement & influence

• Management support

• Level of complexity & risk

• Management of implementation

Systems Development Approaches• Traditional systems lifecycle

• Prototyping

• Application software packages

• End-user development

• Outsourcing

Traditional Systems Lifecycle• Variation of systems development cycle

• Oldest method for building ISes, necessary for large, complex projects.

• Steps:– Project definition– systems study– Design– Programming– Installation– Postimplementation

Other Approaches: Prototyping• Create an experimental system rapidly and

inexpensively for end-users

• Steps:– Identify the user’s basic requirements.– Develop an initial prototype.– Use the prototype. – Revise & enhance the prototype.

• Iterative approach: repeat the process.

• Especially good for end-user interfaces.

Other Approaches: Application Software Packages

• Buying a premade, prepackaged application software package.

• Prewritten code can often fulfill most requirements of an proposed IS.

• Customization– Can be modified to meet needs better with optional

add-ons.

Application Software Packages: Examples

Accounts receivable; Bond & stock management; Computer-aided design (CAD) ; document imaging; E- mail; Enterprise Resource Planning (ERP); Groupware; Health care; Hotel Management; Internet telephone; Inventory control; Job costing; Library systems; Life insurance; Mailing labels; Mathematical / statistical modeling; Order processing; Payroll; Process control;Tax accounting; Web browser; Word processing

Other Approaches: End-User Development

• End-users develop information system with little help from technical specialists using 4th Generation tools.

• Advantages:– Increased user satisfaction– Improved requirements determination– Reduced applications backlog for IS dept.

• Disadvantages:– Relatively inefficient, rarely scalable– May hamper updating systems & requirements

Other Approaches: Outsourcing

• Contracting– Computer center operations– Telecommunications networks– Application development to external vendors

Systems-Building Methodologies• Structured methodologies

– Structured analysis– Structured design– Structured programming

Structured Methodologies• Techniques are step-by-step, each step building

on the last one.– Structured analysis– Structured design– Structured programming

Structured Analysis• Widely used to define inputs, processes, and

outputs.

• Logical, graphical model of information flow

• Primary tool: Data Flow Diagram (DFD)

• Process specifications describe the transformation occurring within the lowest level of the data flow diagram. They express the logic for each process.

Symbols for Data Flow DiagramsDATA FLOWDATA FLOW

PROCESSPROCESS

SOURCESOURCEOR SINKOR SINK

FILEFILE

Data Flow Diagram (DFD)

GENERATE BILL

CUSTOMER

GENERATE BALANCE

GENERATE REPORT

MANAGER

PAYMENTFILE

CUSTOMERFILE

Structured Design• A set of design rules and techniques that

promotes program clarify & simplicity.

• Reduces effort of coding, debugging, etc.

• Documented in a structure chart:– Top-down chart, showing each level of design & its

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