The United Kingdom Awarding Body (UKAB) has asked me to design a system for the monitoring of its post-examinations re-marks. If a centre feels that the grade awarded to a candidate for an examination is lower than expected, the centre can ask for that script to be remarked. The UKAB expects all this to be completed within three weeks. All the details must be stored for the purpose of analysis and monitoring File Design External file name: Re-Mark. dat General name: Re-mark Description: Stores details of all current candidates Record structure Field name.
Data to be input: The following details will be stored for the re-marks: Subject Reference Code Grade boundaries for grades A-E and U Date for the request of the re-mark Data to be output: Print out of all candidates remarks details Print out of all specific centre number Print out of all specific subject reference code.
Print out of all re-marks that have not been returned in a three week period Print out of all re-marks were the grade have been affected Analysis of software I have decided that there are four possible roots which I can follow to complete this project: will next analyse the pros and cons of each method of completing this task. Database: A database is a very easy way, for a relatively low trained user, to enter data. Once the database has been set up the user can easily input data into the relevant fields.
The database creator can create simple methods of data entry, such as Boolean fields, which makes the data entry more effective and reduces the risk of incorrectly entered data. A new record for each customer would be a simple and practical method that could be implemented. This would also provide the basis for a report, which could be more easily created on a database than on a spreadsheet. Data validation is easily implemented on the database package, with different types of validation, such as currency, Boolean, more than, less than, etc.
The presentation of the data is more than adequate on a database. Statistical analysis and mathematical functions are impossible to undertake on a database, details would need to imported and exported between a database and a spreadsheet. This means that if a database were to be used it would have to be used in conjunction with a spreadsheet package; therefore it seems slightly pointless to use a database, because a comprehensive spreadsheet package could do all the functions to complete this task. Spreadsheet: Setting-up a spreadsheet can be undertaken with relative ease.
The clear advantage spreadsheets have over and above the other options is the ease of entering mathematical formula and the ease with which numbers can be processed. Unlike the other packages in which data must be exported and imported through different packages, the spreadsheet is capable of completing all aspects of the task. Within the spreadsheet package there is also the opportunity to link sheets, which in this task will prove essential. Validating data in a spreadsheet is a very simple operation, once a cell has been chosen Validation can be selected from the Data menu.
Different types of validation can then be performed on the cells contents. The presentation of the data can be arranged well and easily. Using buttons with macros can make printing and saving operational from the actual spreadsheet page, rather than the user having to use menus. When the form of the spreadsheet has to be designed it is harder to accomplish what you want, the cells must be stretched or shrunk, unlike a database in which the form can be specified very easily. Bespoke program: The layout, style, form and function of a bespoke program could be tailored exactly to the user’s requirements.
The program would allow the least computer literate person to use the program; this is because that with enough programming the program created would have the complex workings hidden under a user-friendly face. Out of all the possible options a well-designed bespoke program would work most successfully. But to gain this high level success a vast amount of time would have to be spent creating the program. Updating the program by a relatively low trained employee would be comparably harder than with the other options.
It is the limiting factor of time that will prevent me from using a program over and above the other methods; the feasibility of the program is not very high. Website: With a web site it would be easy to make the user interface and the structure for the application, with very positive results. But when a website is used no mathematical formulae can be entered. All formulae would have to be entered via the spreadsheet and then imported to the website. It seems unnecessary to use a website because I could very easily cut out the “middle-man” and use the spreadsheet instead, since it has the capabilities to link pages very easily as well.
Form Design Report Design Data Validation ; Integrity There are a number of checks that I will carry out to ensure that data are correct whilst entering the data in the system. I will consider that information is available to the system at the point of data entry before validation method.
Input 1. Numerical check Integrity Errors will be detected as easily as possible to minimise the time and effort needed to rectify the adverse effect. A number of validations can be used as said above The data held in a computer system may become incorrect, corrupted or of ‘poor quality’ in many different ways and at many stages data processing Errors on import- data that is keyed in wrongly transcribed. A batch of transaction data could go astray, or keyed in twice by mistake Errors in operating procedure- an update program could for example be run in twice in error and quantities on a master file would then be updated twice.
Program errors- these could lead to corruption of files, a new system may have errors in it that will not surface for the same time or errors may be introduced during program maintenance. Viruses- files can be corrupted or deleted if a disk becomes infected with a virus Transmission errors- interfaces or noise in a communication link may cause bits to be wrongly received Data Security I will maintain data security by keeping data safe from the various hazards to which in may be subjected. These include: Natural hazards such as fire, floods or hurricanes
Deliberate corruption or destruction of data by malicious or terrorists acts Illegal access to ‘hackers’ Accidental destruction by hardware failure or program or operator error Passwords Passwords will be applied to computer systems so that users cannot access the data unless they know the password. Password can also be applied to individual files so that hierarchy of passwords may exist. Password will be changed regularly in case they become generally known. Backups I will make it possible to back up a file by creating another copy, typically on a magnetic tape.
This version can be copied again so that three copies are in existence. One of these will be taken to another location or placed in a fireproof safe as a protection against fire. System Design When I am design the system I will take into account the hardware and software that are available. I will design the human-computer interface in such a way that the user will find in straight away to use. Documentation The documentation is appropriate to the design feature that is being described. System flowcharts- these describe the flow of the data around the system Entity relationship diagrams- these show the design of a data model
Structure diagrams- these are means of showing the design of a program or system. They consist of charts showing the system or programs broken down into a number of levels. Hierarchy charts- these are used to show a menu hierarchy or a directory hierarchy Human-computer interface (HCI) The HCI will be designed carefully with the following number of options available: Keyboard input that may involve a command language * WIMP environment Direct manipulation, embed the system within a device A command line interface using a keyboard is appropriate, but often a WIMP interface is appropriate.
In this case a WIMP environment it is important that standards are adhered to so that the user can be confident of consistency between different screens. Test Data Testing the system, the data issued with the specification can now be tested to see if the system works properly, the details of these are below:.