ALTERNATIVE METHODS FOR BUILDING INFORMATION SYSTEMS

There are a number of alternative methods for building information systems, each suited to different types of problems.

1.         SYSTEMS LIFE CYCLE

The oldest method for building systems is the systems life cycle, which requires that information systems be developed in formal stages. It partitions systems development process into formal stages that must be completed sequentially.

The stages have defined outputs; each requires formal approval before the next stage can commence. The system life cycle is useful for large projects that need formal specifications and tight management control over each stage of systems building.

Any  systems life cycle should result in a high quality system that meets or exceeds customer expectations, reaches completion within time and cost estimates, works effectively and efficiently in the current and planned Information Technology infrastructure, and is inexpensive to maintain and cost-effective to enhance

The oldest of these, and the best known, is the waterfall: a sequence of stages in which the output of each stage becomes the input for the next. These stages can be characterized and divided up in different ways, including the following:

1. Analysis - Here the system requirements are gathered and defined.  Any existing systems can also be evaluated and any inefficiency can be highlighted.
2. Design - A design specification is derived from requirements analysis, where plans are made concerning physical construction, hardware, operating systems, programming, communications and security issues.
3. Build - Using the design specification, the system is developed and components built.  Additionally, the system will also be tested and user training will occur.
4. Implement - The system is installed and implemented.  This can be through either a gradual phased process or through a more cost effective launch of the complete system.
5. Operation and Maintenance - For a system to remain effective it must be constantly monitored and evaluated.  Regular maintenance will ensure the integrity of the system.

Advantages:

• Easy to understand
• Quality built-in throughout
• Configuration management
• Clear and defined stages
• Forced to do analysis and design first

Disadvantages:

• Time between agreeing requirements and delivery of final product
• Risk in confirming customer requirements and user-interface, as there is no revision
• Based on paper
• this approach is  very rigid and  costly
• Not well suited for unstructured, decision-oriented applications for which requirements cannot be immediately visualized.

2.         PROTOTYPING

Prototyping consists of building an experimental system rapidly and inexpensively for end users to interact with and evaluate. The prototype is refined and enhanced until users are satisfied that it includes all of their requirements and can be used as a template to create the final system.

Prototyping encourages end-user involvement in systems development and iteration of design until specifications are captured accurately (Warfel, 2009).  Approved prototype serves as template for final system.

Steps in Prototyping

1. Identifying user’s basic requirements
2. Developing initial prototype
3. Using prototype
4. Revising and enhancing prototype

Advantages of prototyping

·         Useful if some uncertainty in requirements or design solutions

·         Often used for end-user interface design

·         Reduces development time.

·         Reduces development costs.

·         Requires user involvement.

·         Developers receive quantifiable user feedback.

·         Facilitates system implementation since users know what to expect.

·         user requests are easier to determine, helping to produce a system that better meets the users' needs; and results in greater user satisfaction

·         Exposes developers to potential future system enhancements.

·         systems are easier for end-users to learn and use because they are more involved in the development process

Disadvantages of prototyping

·         May gloss over essential steps in systems development if done rapidly

·         May not accommodate large quantities of data or large number of users

·         May result in system that is that are technically inadequate for a production environment

·         The rapid creation of prototypes can result in systems that have not been completely tested or documented

·         Developer misunderstanding of user objectives

·         Excessive development time of the prototype

·         Expense of implementing prototyping

·         Can lead to insufficient analysis.

·         Users expect the performance of the ultimate system to be the same as the prototype.

·         Developers can become too attached to their prototypes

·         Can cause systems to be left unfinished and/or implemented before they are ready.

·         If sophisticated software prototypes (4th GL or CASE Tools) are employed, the time saving benefit of prototyping can be lost.

3.         APPLICATION SOFTWARE PACKAGE

These are a Set of pre-written, pre-coded application software programs commercially available for sale or lease.

Developing an information system using an application software package eliminates the need for writing software programs when developing an information system. These programs are called application packages because they direct the processing required for a particular use, or application, which users want to accomplish (Shin & Lee, 1996)

Using a software package reduces the amount of design, testing, installation, and maintenance work required to build a system. Application software packages are helpful if a firm does not have the internal information systems staff or financial resources to custom develop a system.

Application packages are generally designed to support commonly performed business functions and appeal to multiple types of user organizations. Although a package may be tailored to a user's specific needs through parameters or tables, the software itself is not individualized to a given organization in the same way that custom-designed, custom-coded software would typically be tailored.(Gross & Ginzberg, 1984) Examples of application packages include accounting systems, human resources software, and enterprise resource planning (ERP) software.

Advantages:

·         Save time and money

·         Many offer customization features. Software can be modified to meet unique requirements without destroying integrity of package software

·         Functions provided by the package include  flexibility, user friendliness, hardware and software resources, database requirements, installation and maintenance efforts, documentation, vendor quality, and cost 

Disadvantages:

·         To meet an organization’s unique requirements, packages may require extensive customization that can substantially raise development costs. customization is the modifications of software package to meet organization’s unique requirements without destroying the software’s integrity

References

Beringer, J., Fischer, G., Mussio, P., Myers, B., Paternò, F., & de Ruyter, B. (2008). The next challenge: from easy-to-use to easy-to-develop. are you ready? CHI  ’08 extended abstracts on Human factors in computing systems, CHI EA  ’08 (pp. 2257–2260). New York, NY, USA: ACM. doi:10.1145/1358628.1358663

Brown, D., & Wilson, S. (2012). The Black Book of Outsourcing: How to Manage the Changes, Challenges, and Opportunities. John Wiley & Sons.

Costabile, M. F., Dittrich, Y., Fischer, G., & Piccinno, A. (2011). End-User Development: Third International Symposium, IS-EUD 2011, Torre Canne, Italy, June 7-10, 2011, Proceedings. Springer.

Gross, P. H., & Ginzberg, M. J. (1984). Barriers to the Adoption of Application Software Packages. SSRN eLibrary. Retrieved from http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1290109

Shin, H., & Lee, J. (1996). A process model of application software package acquisition and implementation. Journal of Systems and Software, 32(1), 57–64. doi:10.1016/0164-1212(95)00045-3

Warfel, T. Z. (2009). Prototyping: A Practitioner’s Guide (1st ed.). Rosenfeld Media.