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Systems Selection

21 September, 2015 - 11:32

As you can see in Figure 7.1, systems selection lies between structured systems analysis (bubble 2.0) and structured systems design (bubble number 4.0). Systems selection uses the new system’s functional requirements (the logical specification) and physical requirements that were developed in the analysis phase to decide what resources will be used to implement the new system. Only after the resources are chosen does detailed design begin.

Review Question

What is systems selection?

 

Systems selection is a set of procedures performed to choose the computer software and hardware for an Information System. The systems selection goals are to:

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  • Determine what computer software will implement the logical specification developedin structured systems analysis. We must decide between in-house software development by Information Systems personnel, end-users, or contract programmers versus off-the-shelf rental or purchase. For instance, we should consider whether home grown systems can provide the level of integration and functionality that could be achieved through use of an enterprise system.
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  • Determine what computer hardware will satisfy the physical requirements establishedin structured systems analysis. We must evaluate and choose the architecture (e.g., client/server, LAN) and the type, manufacturer, and model of each piece of computer equipment. 1 In making our choice, we should also be aware of the implications for security and control of Information Systems. Additionally, to understand cost implications, consideration should be given in the decision to environmental controls (i.e., temperature, electrical, etc.).
 
  • Choose acquisition financing methods that are in the best interest of the organization.We must decide whether it is better to purchase, rent, or lease the computer equipment. In addition, we must decide if our data center will be completely within our control or if we will use an applications service provider, or other outsourcing option.
 
  • Determine appropriate acquisition ancillaries. We must establish contract terms, software site-licensing arrangements, computer maintenance terms, and software revision procedures and responsibilities.
 

Review Question

What are systems selection goals?

 
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Before we proceed, let’s look at the sequence of activities presented in Figure 7.1 and in these goals. Historically, the logical specification and the physical requirements were developed in the systems analysis step after the business processes had been documented and accepted, or remodeled (e.g., business process reengineering). Then, a software package would be chosen (and modified, if necessary) or developed in house. This is the sequence depicted in Figure 7.1 and used in this text. As we said in Chapter 6, however, when we implement an enterprise system we change the sequence of activities. With enterprise system implementations we start by choosing the package and then retrofit business processes to match those required by the enterprise system. So, while we present the sequence of the SDLC as “typical,” we ask you to be aware of the existence of practical variations in these activities.