1 Chapter 13 (Week 13) SYSTEMS MAINTENANCE AND EVALUATION Chapter 13: SYSTEMS MAINTENANCE AND EVALUATION Throughout its life, a system should operate effectively and efficiently. To do this, the system needs to be maintained and its users need to be supported. This should be an ongoing process to make sure that the system continues to meet requirements. The operational characteristics of the system will be reviewed continually.

2 Types of maintenance There are three types of maintenance activity. a) Corrective Maintenance is action taken in response to a problem. CM is carried out when there is a systems failure of some kind, for example in processing or in an implementation procedure or when errors are detected in a system and need to be corrected. Its objective is to ensure that systems remain operational. Chapter 13: SYSTEMS MAINTENANCE AND EVALUATION

3 b) Perfective Maintenance is carried out in order to perfect the software, or to improve software so that the processing inefficiencies are eliminated and performance is enhanced. Perfective Maintenance is carried out to include new capabilities/modifications to existing functions and thereby bringing general enhancements to the system. The replacement of a word processing package written for DOS by a package which offers a Windows environment is an example of perfective maintenance. Chapter 13: SYSTEMS MAINTENANCE AND EVALUATION

4 c) Adaptive Maintenance is carried out to take account of anticipated changes in the processing environment. For example new taxation legislation might require change to be made to payroll software. AM occurs when the environment changes. For e.g, when the regulations for the number of of local leaves entitled to staff changes – the system needs to be modified to reflect those new regulations. d) Preventive Maintenance when necessary actions are taken to improve future maintainability or reliability OR to provide a better basis for future enhancements. For e.g, preventive maintenance may be accomplished by replacing the cell every 2-3 years, cleaning the motherboard (removal of dust), performing a disk scan on the HD etc.

5 Chapter 13: SYSTEMS MAINTENANCE AND EVALUATION The causes of systems maintenance Besides environmental changes, three factors contribute to the need for maintenance. Errors:However carefully and diligently the systems development staff carry out systems testing and program testing, it is likely that bugs will exist in a newly implemented system. Changes in requirements: Although users should be consulted at all stages of systems development, problems may arise after a system is implemented because users may have found it difficult to express their requirements.

6 Poor documentation: If old systems are accompanied by poor documentation, or even a complete lack of documentation, it may be very difficult to understand their programs. It will be hard to update or maintain such programs. Chapter 13: SYSTEMS MAINTENANCE AND EVALUATION In-house maintenance With large computer systems, developed by the organisation itself, in-house systems analysts and programmers might be given the responsibility for software maintenance.

7 Chapter 13: SYSTEMS MAINTENANCE AND EVALUATION To ensure that maintenance is carried out efficiently, the principles of good programming practice should be applied. – a)The new program requirements must be specified in full and in writing. These specifications will be prepared by a systems analyst. A programmer should use these specifications to produce an amended version of the program. b)In developing a new program version, a programmer should keep working papers. He or she can refer back to these papers later to check in the event that there is an error in the new program.

8 c)The new program version should be tested when it has been written. A programmer should prepare test data and establish whether the program will process the data according to the specifications given by the systems analyst. d)Each version of a program should be separately identified, to avoid a mix-up about what version of a program should be used for ‘live’ operating. Chapter 13: SYSTEMS MAINTENANCE AND EVALUATION

9 Software maintenance Chapter 13: SYSTEMS MAINTENANCE AND EVALUATION With purchased software (whether off the shelf or bespoke), the software house or supplier is likely to provide details of any new versions of the software as they are produced, simply for marketing purposes. Maintenance contracts There is also likely to be an agreement between the supplier of software and the customer for the provision of a software support service.

10 A maintenance contract typically includes the following services. (a)Help When a customer runs into difficulties operating the system help will initially be given by a telephone hot line’. If a telephone call does not resolve the problem, the software expert may arrange to visit the customer’s premises, although this would be rare for standard packages. (b)Information Extra information about using the package may be provided through factsheets or a magazine sent free to subscribers. Chapter 13: SYSTEMS MAINTENANCE AND EVALUATION

11 (c)Updates Free updates are provided to correct errors in part of a package, or if there is something inevitable that will mean that some aspect of a package has to be changed. (d) Upgrades When the whole package/hardware is revised just after purchase of it, the contract provides for customers to get the NEW version at a heavily discounted price. Upgrades often include new features not found in the previous versions of the software/hardware. Chapter 13: SYSTEMS MAINTENANCE AND EVALUATION

12 (e) Legal Conditions There should be provisions about the duration of the contract and in what circumstances the contract may be TERMINATED. This covers: the customer’s obligations to use the software in the way it was intended to be used (not to make ILLEGAL copies of the CDs or manuals), on the right sort of hardware. The liability of the supplier will also be set out, especially regarding consequential loss.

13 Hardware maintenance Computer hardware should be kept serviced and maintained too. Maintenance services are provided: (a)by the computer manufacturers themselves; or (b)by third-party maintenance companies. Maintenance of hardware can be obtained in two ways. On a contract basis. PC maintenance contracts are usually negotiated annually. On an ad hoc basis - ie calling in a maintenance company whenever a fault occurs. Chapter 13: SYSTEMS MAINTENANCE AND EVALUATION