adv ais other dev approaches

T OPIC SEVEN

© 2012 UMT Advanced Accounting Information Systems 1

Other AIS Development Approaches

INTRODUCTION

• We’ll also discuss how to hasten or

improve the development process through:

– Business process reengineering

– Prototyping


– Prototyping

– Computer-aided software engineering (CASE) tools

BUSINESS PROCESS REENGINEERING

• Business process reengineering (BPR) is the analysis and redesign of business processes and information systems to achieve significant performance improvements.


improvements.– Reduces a company to its essential business

processes.

– Reshapes organizational work practices and information flows to take advantage of technological advancements.


• BPR:

– Simplifies the system.

– Makes it more effective.

– Improves a company’s quality and service.


– Improves a company’s quality and service.

• BPR software has been developed to help

automate many BPR tasks.


• Michael Hammer has set forth several principles that help organizations successfully reengineer business processes:

- Organize around outcomes, not tasks.


• DO AWAY WITH: Assigning different parts of a business process to different people, with the resulting handoffs, delays, and errors.

• INSTEAD: Each person’s job is designed around an objective, outcome, or process rather than a task needed to complete a process.





- Require those who use the output to perform the process.


� Michael Hammer has set forth several principles that help organizations successfully reengineer business processes:



- Require those who use the output to perform the

process.

- Require those who produce information to process it.




• You centralize operations to achieve economies of scale and eliminate redundancy.

• You decentralize operations to be more responsive to customers and provide better service

• With technology, you don’t have to choose.



process.


- Centralize AND disperse data.

• With technology, you don’t have to choose.

– Corporate-wide databases centralize data.

– Telecommunications technology disburses it to the organization.






process.



- Integrate parallel activities.

� Example: In developing a new product, include on the development team at least one person from each involved department, so the right hand will know what the left hand is doing and the process will be smoothly integrated.




• In a traditional system, there is a layer of worker bees and several layers of manager bees, auditor bees, and controller bees.



process.




- Empower workers, use built-in controls, and flatten the organization chart.

auditor bees, and controller bees.

• In a reengineered system, the people who do the work have decision-making responsibility.

– Information technology enables their decision accuracy.

– Controls are built into the process itself.


• Michael Hammer has set forth several principles that help organizations successfully reengineer business processes:- Organize around outcomes, not tasks.



- Require those who use the output to perform the process.




- Empower workers, use built-in controls, and flatten the organization chart.

- Capture data once—at its source.

• Instead of having each functional area running its own AIS and entering the same data, use source data automation, EDI, etc. to capture data electronically at the source and disburse it to where it needs to be used.


• Underlying reengineering is the efficient

and effective use of the latest information

technology, e.g.:

– Radio- and satellite-based communications.


– Radio- and satellite-based communications.

– Powerful handheld computers.

– Image processing that lets multiple users handle a document simultaneously.

– Active documents.


• Challenges faced by reengineering efforts:

– Many BPR efforts fail or fall short of their objectives. A

company must overcome the following obstacles:

• Tradition

• “We’ve always done it this way!”


• “We’ve always done it this way!”

• Success requires changes in culture and beliefs.


• Challenges Faced by Reengineering Efforts:



• Tradition

• Resistance


• Resistance

• Change is always met with resistance.

• Requires continual reassurance, persuasion, and support.





• Tradition

• Resistance


• Resistance

• Time and cost requirements

• Two or more years are required to complete BPR.





• Tradition

• Resistance


• Resistance


• Lack of management support

• Managers are nervous about the “big hype—few results” syndrome.

• Without their support, the effort will fail.





• Tradition

• Resistance


• Resistance



• Skepticism

• BPR is sometimes viewed as just the same picture in a different frame.





• Tradition

• Resistance


• Resistance



• Skepticism

• Retraining

• The necessary retraining costs time and dollars.





• Tradition

• Resistance


• Resistance



• Skepticism

• Retraining

• Controls

• Cannot skip the inclusion of controls to ensure reliability and integrity.

INTRODUCTION

• We’ll be discussing how to obtain a new information system by:

– Purchasing prewritten software

– Developing software in-house


– Outsourcing

• We’ll also discuss how to hasten or improve the development process through:

– Business process reengineering

– Prototyping

– Computer-aided software engineering (CASE) tools

PROTOTYPING

• Prototyping is an approach to systems design in which a simplified working model of a system is developed.

– The prototype (first draft) is built quickly at low cost

and provided to users for experimentation.


and provided to users for experimentation.

– Playing with the prototype allows users to determine

what they do and do not like.

– Developers modify the system in response to user

comments and re-present it to them.

– The iterative process continues until users are

satisfied that the system meets their needs.

PROTOTYPING

• The basic premise is that it’s easier for

people to express what they like or dislike

than to imagine what they want in a

system.


system.

– In another words, it helps to have a straw man to aim at.

– Even a simple system that is not fully functional demonstrates features far better than graphics and verbiage.

PROTOTYPING

• Developers who use prototyping still go through the systems development life cycle.

• But prototyping allows them to expedite some analysis and design.


analysis and design.

• For example, prototyping captures user needs and helps developers and users make many conceptual and physical design decisions.

• Current practice leans heavily toward prototyping so that projects can be completed quickly.

PROTOTYPING

• Four steps are involved in developing a

prototype:

– STEP ONE: Identify basic requirements

– STEP TWO: Develop an initial prototype



– STEP THREE: Repeated iterations

– STEP FOUR: Use the system

PROTOTYPING


prototype:







PROTOTYPING

• The first step is to identify basic requirements by meeting with users to agree on the size and scope of the system and decide what it should include and exclude.


exclude.– Developer and users also determine:

• Decision-making and transaction processing outputs.

• Inputs and data needed to produce those outputs.

– The emphasis is on what outputs should be produced rather than how.

PROTOTYPING

– The developer must ensure:

• User expectations are realistic.

• Their basic information requirements are met.

– The designer uses the information


– The designer uses the information requirements to develop cost, time, and feasibility estimates for alternative AIS solutions.

PROTOTYPING


prototype:







PROTOTYPING

• The second step involves developing an

initial prototype that meets the agreed-on

requirements.

– Emphasize speed and low cost rather than


– Emphasize speed and low cost rather than efficiency of operation.

– The goal is to implement the prototype within a short time period.

PROTOTYPING

• Because of time constraints, some

aspects are sacrificed. For example, at

this point, you ignore:

– Non-essential functions


– Non-essential functions

– System controls

– Exception handling

– Validation of input data

– Processing speed

– Efficiency considerations

PROTOTYPING

• Users must see and use tentative versions of:

– Data entry display screens

– Menus

– Input prompts


– Source documents

• They must also:

– Respond to prompts

– Query the system

– Judge response times

– Issue commands

PROTOTYPING

• When the prototype is finished, the

developer returns to the users and

demonstrates the system.

• Users are instructed to:


• Users are instructed to:

– Experiment.

– Comment on what they do and do not like.

PROTOTYPING


prototype:







PROTOTYPING

• The third step involves repeated iterations

of:

– Users identifying changes.

– Developers making the changes.


– Developers making the changes.

– The system being turned back to users for next round.

• This step continues until users are

satisfied—usually 4 to 6 iterations.

PROTOTYPING


prototype:







PROTOTYPING

• The final step involves using the system

approved by the users.

• An approved prototype is typically used in

one of two ways.


one of two ways.

PROTOTYPING

• Half of the prototypes are turned into fully

functional systems referred to as

operational prototypes.

– To make them operational, the developer


– To make them operational, the developer must:

• Add needed controls.

• Improve operational efficiency.

• Provide backup and recovery.

• Integrate the prototype with the systems with which

it interfaces.

PROTOTYPING

• Changes may be necessary to allow the

program to:

– Accept real input.

– Access real data files.


– Access real data files.

– Process data.

– Make necessary computations and calculations.

– Produce real output.

PROTOTYPING

• When it’s not practical to modify the

prototype to make a fully functional

system, non-operational or throwaway

prototypes can be used in several ways:


prototypes can be used in several ways:

– They may be discarded, and the systems requirements identified in the process of building them can be used to develop a new system.

• If so, the SDLC is followed to develop the system,

and the prototype is a model.

PROTOTYPING

– Alternately, they may be used as the initial prototype for an expanded system designed to meet needs of many users.

– As a final alternative, if users and developers


– As a final alternative, if users and developers decide the system is unsalvageable, the prototype can be discarded completely.

PROTOTYPING

• When to use prototyping

– Prototyping supports rather than replaces the SDLC.

– It is appropriate when:

• Users don’t fully understand their needs, or the needs

change rapidly.


change rapidly.

• System requirements are difficult to define.

• System inputs and outputs are not known.

• The task to be performed is unstructured or semi-structured.

• Designers are uncertain about what technology to use.

• The system is crucial and needed quickly.

• The risk of developing the wrong system is high.

PROTOTYPING

• The users’ reactions to the new system are important

development considerations.

• Many design strategies must be tested.

• The design staff has little experience developing this type of

system or application.

• The system will be used infrequently so that processing


• The system will be used infrequently so that processing

efficiency is not crucial.

PROTOTYPING

• Good candidates for prototyping:

– Decision support systems.

– Executive information systems.

– Expert systems.


– Expert systems.

– Information retrieval systems.

– Systems that involve experimentation and trial-and-error development.

– Systems in which requirements evolve as the system is used.

PROTOTYPING

• Prototyping is usually inappropriate for:

– Large or complex systems that:

• Serve major organizational components; or

• Cross numerous organizational boundaries.


• Cross numerous organizational boundaries.

– Standard AIS components, such as:

• Accounts receivable

• Accounts payable

• Inventory management

PROTOTYPING

• Advantages of prototyping:

– Better definition of user needs• Because of intensive end-user involvement.


PROTOTYPING


– Better definition of user needs

– Higher user involvement and satisfaction


PROTOTYPING




– Faster development time



• It may take days or weeks to get a prototype up vs. a year or more for a traditional system.

PROTOTYPING







– Fewer errors

• Errors are detected early because the users experiment with each version.

• It’s also easy to identify and terminate an infeasible AIS early.

PROTOTYPING







– Fewer errors

– More opportunity for changes

PROTOTYPING







– Fewer errors

– More opportunity for changes

– Less costly• Some for 10–20% of the cost of traditional systems.

PROTOTYPING

• Disadvantages of prototyping:

– Significant user time


PROTOTYPING



– Less efficient use of system resources

• Shortcuts in developing the system may


• Shortcuts in developing the system may result in:

– Poor performance and reliability

– High maintenance and support costs

PROTOTYPING




– Incomplete system development



PROTOTYPING







– Inadequately tested and documented systems

• Who wants to do that stuff?

PROTOTYPING








– Negative behavioral reactions• If the prototype is discarded, users may be upset

about using it and losing it.

• May also be dissatisfied if all their suggestions are not incorporated or if they have to go through too many iterations.

PROTOTYPING








– Negative behavioral reactions

– Never-ending development• If not managed properly, the development could get

stuck in a terminal loop.

Computer-Aided Software Engineering (CASE) Tools

• Traditionally, software developers have created software to simplify the work of others, but not for themselves.

• Computer-aided software (or systems) engineering (CASE) tools are an integrated


engineering (CASE) tools are an integrated package of computer-based tools that automate important aspects of the software development process.– Used to plan, analyze, design, program, and maintain

an information system.

– Also used to enhance efforts of managers, users, and programmers in understanding information needs.


• CASE tools do not replace skilled

designers, but provide developers with

effective support for all SDLC phases.

• CASE software typically includes tools for:


• CASE software typically includes tools for:

– Strategic planning

– Project and system management

– Database design

– Screen and report layout

– Automatic code generation


• Advantages of CASE technology:

– Increased productivity• Can generate bug-free code from system

specifications.

• Can automate repetitive tasks.


• Can automate repetitive tasks.



– Increased productivity

– Improved program quality

• Can simplify enforcement of structured


• Can simplify enforcement of structured development standards, which:

– Improves quality of development.

– Reduces threat of serious design errors.

• Can check internal accuracy of design and detect inconsistencies.





– Cost savings


– Cost savings

• Cost savings of up to 80–90% are possible.





– Cost savings


– Cost savings

– Improved control procedures

• Encourages development early in the design process of:

– System controls

– Security measures

– System auditability

– Error handling procedures





– Cost savings


– Cost savings

– Improved control procedures

– Simplified documentation� Automatically documents as the system

development progresses.


• Problems with CASE technology:

– Incompatibility• Some tools don’t interact effectively with

some systems.




– Incompatibility

– Cost • Some packages > $360,000.




– Incompatibility

– Cost

– Unmet expectations


– Unmet expectations

• Only 37% of CIOs believe they achieved expected benefits.

SUMMARY AND CONCLUSIONS

• You’ve learned:

– What reengineering processes entail and when they are appropriate.

– How prototypes are used to develop an AIS


– How prototypes are used to develop an AIS and when it is advantageous to do so.

– What computer-aided software engineering is and how it’s used in systems development.

adv ais other dev approaches

Documents

development process

better business processes

redesign of business

essential business processes

information flows

business traditional

help organizations

bpr tasks