The sorts of question that would need to be asked include the follow ing.
• Is a data orientated or a control orientated system to be implemented?
•Data orientated' systems generally mean information systems that will have a considerable database. 4Control orientated' systems refer to embedded control systems. These days it is not uncommon to have systems w ith components of both types.
• Will the software that is to be produced be a general package or application specific? An example of a general package would be a spreadsheet or a word processing package. An application specific package could be. for example, an airline seat reservation system.
• Is the system to be implemented of a particular type for which specific tools have been developed? For example:
The soft systems approach is described in Checkland. P and Scholes. J.. Soft systems methodology in action, John Wiley and Sons. 1990.
We first introduced the difference between information systems and embedded systems in Chapter 1.
• does it involve concurrent processing? - if so the use of techniques appropriate to the analysis and design of such systems would be considered;
• will the system to Ih> created be knowledge-based? - expert systems have a set of rules which result in some 'expert advice' w hen applied to a problem domain (sets of methods and tools have been developed to assist in the creation of such systems); or
• w ill the system to be produced make heavy use of computer graphics?
• Is the system to be created safety-critical? For instance, could a malfunction in the system endanger human life?
• What is the nature of the hardware/software environment in which the system will operate? It might be that the environment in which the final software will operate is different from that in which it will be developed. Embedded software may be developed on a large development machine that has lots of supporting software tools in the way of compilers, debuggers, static analysers and so on, but might then be down-loaded to a small processor in the larger engineered product. A system destined for a personal computer w ill need a different approach to one destined for a main-frame or a client-server environment.
Exercise 4.1 How would you categorize each of the follow ing systems according to the classification above?
(a) a payroll system
(b) a system to control a bottling plant
(c) a system that holds details of the plans of plant used by a water company to supply water to consumers
(d) a software application to support project managers
(e) a system used by lawyers to get hold of case law relating to company taxation.
When we first embark on a project we might be expected to work out elaborate plans even though we are at least partially ignorant of many important factors that will affect the project. For example, until we do a detailed investigation of the users' requirements we w ill not be able to estimate how much effort w ill be needed to build a system to meet those requirements. The greater the uncertainties at the beginning of the project, the greater the risk that the project will be unsuccessful. Once we recognize a particular area of uncertainty we can. however, take steps to reduce its uncertainty.
One suggestion is that uncertainty can be associated with the products. processes. or resources associated with the project.
Chapter 3 has already touched on some aspects of risk, which are developed further in Chapter 8.
Product uncertainty Here we ask how well the requirements are understood. It might be that the users themselves are uncertain about what a proposed information system is to do. The government, say. might introduce a new form of taxation but the way this is going to operate in detail will not be known until a certain amount of case law has been built up. Some environments can change so quickly that what was a precise and valid statement of requirements rapidly becomes out of date.
Process uncertainty It might be that the project under consideration is the first OMT is an object-oriented where an organization has tried to use a method, such as SSADM or OMT, that is design approach, new to them. Perhaps a new application building tool is being used. Any change in the way that the systems are developed is going to introduce uncertainty.
Resource uncertainty The main area of uncertainty here will almost surely be the availability of staff of the right ability and experience. A major influence on the degree of uncertainty in a project w ill be the sheer size of a project. The larger the number of resources needed or the longer the duration of the project, the more inherently risky it is likely to be.
Furomcthod, which is reviewed briefly in Appendix C, distinguishes between factors that increase uncertainty. for example, continually changing requirements, and those that increase complexity, for example, software size. This is because it suggests different strategies to deal with the two distinct types of risk.
At IOH. Amanda has identified possible staff resistance as a risk to the Exercise 4.2 maintenance group accounts project. Would you classify this as a product, process or resource risk? Perhaps it does not fit into any of these categories and some other is needed.
Brigette at Brightmouth College identified the possibility that no suitable payroll package would be available on the market as a risk. What other risks might be inherent in the Brightmouth College payroll project?
Take into account user recfuirements concerning implementation A user organization lays down standards that have to be adopted by any contractor providing software for them. For example the UK Civil Service favours the SSADM standard where information systems are being developed.
It is common for organizations to specify that suppliers of software have BS EN Chapter 12. Software ISO 9001:1994 or TickIT accreditation. This will affect the way projects are quality, discusses BS EN conducted. ISO 9001 and TickIT.
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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.