Accounting information systems 11e romney steinbart chapter 19

PURCHASING PREWRITTEN SOFTWARE• Purchasing software and the SDLC: – Companies that buy rather than develop software still follow the SDLC process, including: • Systems analysis  They co

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C HAPTER 19

AIS Development Strategies

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• Questions to be addressed in this chapter include:

– How do organizations buy software, hardware, and vendor services?

– How do information systems departments develop custom software?

– How do end users develop, use and control computer-based information systems?

– Why do organizations outsource their information systems, and what are the benefits and risks of doing so?

– How are prototypes used to develop an AIS, and what are the advantages and disadvantages?

– What is computer-aided software engineering, and how is it used in systems development?

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• Companies can experience a number of

difficulties in developing an AIS, including:

– Projects are backlogged for years because of the high demand for resources.

– The newly designed system doesn’t meet user needs – The process takes so long that by the time it’s

complete, it’s obsolete.

– Users can’t adequately specify their needs.

– Changes to the AIS are often difficult to make after requirements have been written into the

specifications.

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• We’ll be discussing how to obtain a new

information system by:

– Purchasing prewritten software;

– Developing software in-house; or – Outsourcing.

• We’ll also discuss how to hasten or improve the

development process through:

– Business process reengineering – Prototyping

– Computer-aided software engineering (CASE) tools

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– Purchasing prewritten software

– Developing software in-house; or – Outsourcing.

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PURCHASING PREWRITTEN SOFTWARE

• In the early days of computers,

companies were rarely able to buy

software to meet their needs.

• But commercially available packages are now outpacing custom-developed software as old systems are replaced.

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• Canned software is sold on the open

market to a broad range of users with

similar requirements.

– Some companies sell hardware and software together as a package.

• These systems are called turnkey systems

• Many are written by vendors who specialize in a particular industry.

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– A major problem with canned software:

• It often does not meet all of a company’s information needs.

• Can be overcome by modifying the canned software.

– Usually best done by the vendor.

– Unauthorized modifications may render the program unreliable and unstable.

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• Companies can also acquire software through

application service providers (ASPs).

– ASPs host Web-based software and deliver it to clients over the Internet.

– Companies don’t have to buy, install, or maintain canned software; they simply “rent” it.

– If you used an online version of a package like Tax to prepare your taxes, that’s a consumer version

Turbo-of renting sTurbo-oftware over the Internet.

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– Advantages of ASPs:

• Reduction of software costs and administrative overhead.

• Automated software upgrades.

• Scalability as the business grows.

• Global access to information.

• Access to skilled IT personnel.

• Ability to focus on core financial competencies rather than IT.

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• Purchasing software and the SDLC:

– Companies that buy rather than develop software still follow the SDLC process, including:

• Systems analysis

 They conduct an initial investigation,

systems survey, and feasibility study, as well as determining AIS requirements.

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• Systems analysis

• Conceptual design

• An important aspect is determining

whether software that meets AIS requirements is already available.

• If so, a make-or-buy decision must be

made.

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• Companies also may design

inputs, outputs, files, and control procedures.

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• Conceptual design

• Physical design

• Implementation and conversion

• These activities must still take place,

including:

– Selecting and training personnel – Installing and testing hardware and software – Documenting procedures

– Converting from old to new AIS

• However, the software modules do not

have to be developed and tested.

• And the computer programs do not need

to be documented.

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• Conceptual design

• Physical design

• Implementation and conversion

• Operation and maintenance

• The AIS is operated like any other software.

• The vendor usually maintains the software.

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• Selecting a vendor

– Deciding whether to make or buy software can be made independently of the decision to acquire hardware, service, maintenance, and other AIS resources.

– And the preceding resources can be bought independently of the software.

– But hardware and vendor decisions may depend on the software decisions.

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• Vendors can be found by:

– Looking in phone book – Obtaining referrals

– Scanning computer or trade magazines – Attending conferences

– Using search organizations

• Beware of fly-by-night companies that can leave your organization high and dry.

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• Acquiring hardware and software

– Once AIS requirements have been defined, the organization can buy software and

hardware.

– Companies needing only a PC and some office software can usually complete their own research and make a selection.

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• When buying large or complex systems, a

request for proposal (RFP) should be

prepared:

– The RFP is an invitation to bidders to propose

a system by a specific date.

– Each proposal is evaluated.

– Finalists are investigated in depth.

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• The formal approach is important for

several reasons:

– Saves time • The same information is

provided to all bidders.

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several reasons:

– Saves time

– Simplifies the decision-making process

• The bidders all respond in the

same format and based on the same information.

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several reasons:

– Saves time – Simplifies the decision-making process

– Reduces errors • Less likely to look over

important factors in evaluating proposals.

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several reasons:

– Saves time – Simplifies the decision-making process – Reduces errors

– Avoids potential for disagreement

• Both parties have the same

expectations and information

in writing.

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• When an RFP is solicited based on exact

hardware and software specifications:

– Total costs are usually lower.

– Less time is required for vendor preparation and company evaluation.

– However, the vendor cannot recommend alternatives.

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• A generalized RFP contains a problem

definition and requests a system that

meets specific performance objectives and requirements.

– Leaves technical issues to the vendor.

– However, makes it more difficult to evaluate proposals.

– May produce more costly bids.

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• Usually, the more information a company

provides to the vendors, the better their chances

of receiving a system that meets their

requirements.

– Detailed specifications should include:

• Required applications

• Inputs and outputs

• Files and databases

• Frequency and methods of file updating and inquiry

• Unique characteristics or requirements – Be sure to distinguish between mandatory and desirable requirements.

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• Evaluating proposals and selecting a system

– Eliminate any proposals that:

• Are missing important information.

• Fail to meet minimum requirements.

• Are ambiguous.

– Those that pass the preliminary screening should be compared with the proposed AIS requirements to

determine:

• If they meet all mandatory requirements.

• How many desirable requirements they meet.

– Finalists can be invited to demo their system using company-supplied data.

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• In reviewing the proposals, you need to

evaluate:

– Hardware – Software – Vendors

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evaluate:

– Hardware

– Software – Vendors

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• Criteria to evaluate hardware include:

• Compatibility with existing

hardware, software, and peripherals

• Performance compared to

competitors

• Cost and availability of

support and maintenance

• Warrantees and guarantees

• Financing arrangements

• Ability to meet mandatory

requirements

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evaluate:

– Hardware

– Software

– Vendors

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• Criteria to evaluate software include:

• Use by other companies

• Satisfaction of other users

• Capability for online

inquiry of files and records

• Vendor upgrades

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evaluate:

– Hardware – Software

– Vendors

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• Criteria to evaluate vendors include:

• Hardware and software

support and maintenance

• Implementation and

installation support

• Quality and

responsiveness of personnel

• Willingness to provide

training

• Responsiveness and

timeliness of support

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• Approaches to comparing system

performance:

– Benchmark problem – Point scoring

– Requirements costing

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performance:

– Benchmark problem

– Point scoring – Requirements costing

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• Benchmark problem

– The new AIS performs a data processing task with input, processing, and output jobs typical

of what would be required of the new system.

– Processing times are calculated and compared.

– The AIS with the lowest time is judged most efficient.

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performance:

– Benchmark problem

– Point scoring

– Requirements costing

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• Point scoring:

– A weight is assigned to each criterion used to evaluate the system, based on the relative

importance of that criterion.

– Each criterion is rated for each product.

– Each rating is multiplied times the weight assigned to the criterion to develop a

weighted score.

– The weighted scores are added for each product.

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• Example:

– Zorba Co is evaluating systems offered by three different vendors: Able Co., Baker Co., and Cook Co.

– Zorba has determined three criteria that they will use

to evaluate the different systems: cost, speed, and vendor reliability.

– They have provided the following weights to each criteria, with vendor reliability being the most critical:

• Vendor reliability—9

• Cost—6

• Speed—4

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• Zorba examined the packages offered by the three

vendors and rated them based on these three criteria

Ratings were from 1–5 with 5 being the highest score.

Criteria Able Co Baker Co Cook Co.

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 The weighted scores are then computed by multiplying

the rating given to each vendor on each criterion times

the weight assigned to that criterion.

Criteria Able Co Baker Co Cook Co.

WEIGHTED SCORES Criteria Able Co Baker Co Cook Co.

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• The weighted scores for each company are

summed:

– Able = 60 points – Baker = 79 points – Cook = 68 points

• Based on the preceding scores, the bid would

probably be awarded to Baker Co.

WEIGHTED SCORES Criteria Able Co Baker Co Cook Co.

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• The preceding example is a simplification

In a real-life scenario, several factors

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performance:

– Benchmark problem – Point scoring

– Requirements costing

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• Requirements costing:

– Estimates cost of purchasing or developing

features that are not included in a particular

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• To verify that the AIS that looks best on

paper is actually the best in practice:

– Test-drive the software.

– Contact other users for references.

– Evaluate vendor personnel.

– Confirm details of the proposal.

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– Purchasing prewritten software

– Developing software in-house

– Outsourcing

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DEVELOPING SOFTWARE IN-HOUSE

• Despite the availability of good canned

software, many organizations develop

their own because:

– Their requirements are unique; or – Their size and complexity necessitates a custom package.

• Developing custom software is difficult and error prone and consumes much time and

resources.

• The GAO reports that

31% of federal government IT projects are poorly planned or do not meet intended

objectives.

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• The most difficult hurdles:

– Lack of time.

– Complexity of desired system.

– Poor requirements and systems planning.

– Inadequate communication and cooperation between departments and users.

– Lack of qualified staff.

– Poor senior executive support.

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• After end users define their requirements,

the analysts:

– Work with the end users to determine the format of paper and screen outputs.

– Identify:

• Data required for each input.

• Data to be retained in files.

– Develop detailed program specs to be interpreted and coded by programmers.

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• The process requires much discipline and

management supervision.

• Accountants may help as project

supervisors, users, or development team

members.

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• Custom software is usually developed and written in-house.

– Alternately, organizations may engage an outside company to develop a package or assemble one from their inventory of modules – These modules are adapted, combined, and organized to form a customized product that meets specific requirements.

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• When contracting with an outside organization,

maintain control over development and observe

the following guidelines:

– Carefully select a developer

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• When contracting with an outside organization,

maintain control over development and observe

the following guidelines:

– Carefully select a developer

– Sign a contract to clearly define responsibilities

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