What is being learnti
The most important reason for having a prototype is that there is a need to leam about an area of uncertainty. For any prototype it is essential that the project managers define at the outset what it is intended to leam from the prototype.
This has a particular relevance to student projects. Students often realize that the software that they are to write as part of their project could not safely be used by real users. They therefore call the software a 'prototype*. However, if it is a real prototype then they must:
• specify what they hope to learn from the prototype;
• plan how the prototype is to be evaluated;
• report on what has actually been learnt.
Prototypes may be used to find out how a new development technique can be used. 'This would be the case where a new methodology is being used in a pilot scheme. Alternatively, the development methods might be well-known, but the nature of the application might be uncertain.
Different projects will have uncertainties at different stages. Prototypes can therefore be used at different stages. A prototype might be used, for instance, at the requirements gathering stage to pin down requirements that seem blurred and shifting. A prototype might, on the other hand, be used at the design stage to test out the users' ability to navigate through a sequence of input screens.
To what extent is the prototyping to /x> donei
It would be unusual for the whole of the application to be prototyped. The prototyping might take one of the following forms, which simulates only some aspects of the target application.
Mock-ups l or example, copies of the screens that the system is to use are shown to the users on a terminal, but the screens cannot actually be used.
Simulated interaction For example, the user can type in a request to access a record and the system will respond by showing the details of a record, but the details shown are always the same and no access is made to a database.
Partial working model:
• vertical - some features are prototyped fully
• horizontal - all features are prototyped but not in detail (for example, there might not be a full validation of input).
The human-computer interface With information systems, w hat the system is to do has usually been established and agreed by management at a fairly early stage in the development of the system. Prototyping tends to be confined to establishing the precise way in which the operators are to interact with the system. In this case, it is important that the physical vehicle for the prototype be as similar as possible to the operational system.
The functionality of the system In other cases, the precise way that the system should function internally will not be known. This w ill particularly be the case w here a computer model of some real-world phenomenon is being developed. The algorithms used need to be repeatedly adjusted until they satisfactorily imitate the behaviour they should be modelling.
At what stage of a system development project (for example, feasibility study. Exercise 4.5 requirements analysis etc.) would a prototype be useful as a means of reducing the follow ing uncertainties?
(a) There is a proposal that the senior managers of an insurance company have personal access to management information through an executive information system installed on personal computers located on their desks. Such a system would be costly to set up and there is some doubt about whether the managers would actually use the system.
(b) A computer system is to support sales office staff who take phone calls from members of the public enquiring about motor insurance and give quotations over the phone.
(c) The insurance company is considering implementing the telephone sales system using the system development features supplied by Microsoft Access. They are not sure, at the moment, that it can provide the kind of interface that would be needed and are also concerned about the possible response times of a system developed using Microsoft Access.
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What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.