Accounting Information System By Rizwan Waheed M.Com 710

Evaluating Alternatives and Strategies This chapter includes the evaluation of alternative solutions, the preparation of the system requirement document and the presentation of the system requirements document to management, it also describes several systems development tools, techniques, and strategies, including prototyping, computer-aided s/w engineering (CASE) tools, system flowcharts and state transition diagrams.

Evaluating S/W Alternatives Make or buy decision Make or buy decision –The choice b/w developing s/w in-house and purchasing s/w is often called make or buy decision Software package Software package –A s/w package is purchased or leased from another company In-house software In-house software –Is developed by the company’s own IS (information System) department Companies that specialize in developing s/w for sale are called S/W publishers or S/W venders Companies that specialize in developing s/w for sale are called S/W publishers or S/W venders

Horizontal application Horizontal application –A software package that can be used by many different types of organizations Vertical application Vertical application –A software package developed to handle information requirements for a specific type of business is called vertical application

Why we develop S/W In-House Satisfy unique requirements Satisfy unique requirements –Commercially available s/w do not meet their unique requirements Minimize changes in business procedures and policies Minimize changes in business procedures and policies Meet constraints of the existing system Meet constraints of the existing system –Any new s/w that is installed must work with existing system Meet constraints of existing technology Meet constraints of existing technology –The new s/w must be compatible with the existing h/w and operating environments

Develop internal resources and capabilities Develop internal resources and capabilities –Many firms feel that in-house IS resources and capabilities provide a competitive advantage because they can respond quickly when business problems or opportunities arise

Reasons for Buying a s/w Packages Lower Costs Lower Costs Require less time to implement Require less time to implement –When we purchase a package, it is already has been designed, tested, programmed and documented Proven reliability and benchmarks Proven reliability and benchmarks Implemented by other companies Implemented by other companies Require less technical development staff Require less technical development staff –Less programmers and system analyst requires in IS department Future upgrades provided by the vendor Future upgrades provided by the vendor

Customizing s/w packages You must decide weather to build your own s/w or to acquire a s/w package that can be customized to meet your specifications. The three ways to customize a s/w packages are 1. For some s/w packages, you might be able to purchase a basic package that can be customized to suit your needs, many s/w vendors offer basic packages that are available in standard versions, with add-on components that can be configured individually. (e.g HR system)

2. You may be able to negotiate directly with the s/w vendor to make enhancements to meet your systems need by paying extra fee for the changes 3. Purchase the package and make your own modifications. This option might be attractive when the product come close to satisfying your requirements and the vendor will not make the requested changes.the disadvantage of this approach is that system analysts and programmers might be unfamiliar with the s/w and will need time to learn the package and make the modification correctly

Other S/W Alterntives Outsourcing Outsourcing –Is the use of outside companies to handle a portion of a company’s workload on a temporary or long-term basis –A contract personnel firm supplies technical help for specific periods of time at a set rate –Another type of outsourcing involve the joint development of a customized vertical application package where a company works together wit an outside software vendor –A major disadvantage of outsourcing is that it raises concerns about job security

End-user systems End-user systems –Are applications that can be operated and mnaged by end-users on their own. Enterprise computing Enterprise computing –Is an overall information management strategy that supports group, departmental and total company information needs. The key is the effective integration of information resources so that users have controlled access to the mainframe data they need to support local system. Many enterprise-computing systems are based on a design concept called client/server architecture