Chapter 1.8 Choosing Applications Software
1.8 (a) Custom Written and Off-the-Shelf Software.
When the analyst has analyzed the problem and come to a conclusion about how it can be solved, a decision has to be made about the software that should be used.
There are many pieces of software that have already been written and are immediately available to buy. This type of software is called ‘off-the-shelf’ software because you can literally go into a computer shop and pick a copy off the shelf. There are a number of advantages in buying an off-the-shelf package:
· The software has already been written and so is immediately available rather than having to wait, sometimes a considerable time, for it to be written.
· The software will be used by many people or organisations, therefore they share the development costs rather than one having to foot the whole bill. This implies that the software will be considerably cheaper.
· Copies of the software have been in use for some time and will have been in use by a variety of users. This means that any bugs in the software should have been found and rectified, consequently it can be expected to work.
· If it comes as part of a suite of software it can be relied upon to be compatible with other applications, allowing, for example, the import of data.
· Because the software will be in general use there are likely to be well established training courses for the staff to be sent on to learn about the software.
A Custom package is one that has been specially written to solve a specific problem. Perhaps there is no freely available piece of software that will satisfy the needs of the company, A piece of custom software should mean that the organisation gets a piece of software that will do all the things that it requires doing, and, equally importantly, does not contain extra routines that will never be used.
1.8 (c) Generic Applications Software.
Word processing.
Used for applications that have the need to communicate with others using text. Writing letters, mail merging, preparing text documents for use in other software packages, are all typical uses of a word processing package.
Spreadsheets.
A spreadsheet is particularly useful because it can store different types of data, including numerical data, and that it can perform calculations on the areas (cells) where the numerical data is being stored.
Desktop publishing (DTP).
This type of software is characterised by the ability to produce a page of printed output that has been designed by using advanced layout techniques. The page may well contain text, graphics, tables and many other types of output each one of which may be better produced using a word processor or a drawing package or a spreadsheet. The value of the DTP is that it contains powerful tools for arranging these individual items on the page, the printout of which can be used directly as the starting point for a printing process. Typically DTP software is used for the production of leaflets, posters, proof copies of books and magazines.
Presentation software.
. The software allows for the preparation of a show which typically follows a storyboard of individual screens. The software allows morphing from one screen to another and also allows animation and full use of text and graphics within individual screens. If required, a soundtrack can be added to complement the pictures being shown.
Drawing packages.
This is a package that produces graphics output. Often such output is exported to a DTP for inclusion in some publication, or to a piece of presentation software for inclusion in a display sequence. Another use for such output is to enliven a page on the world wide web. There are many different forms of graphics package split into groups dependent on the way that the graphic is produced. The two most common are bitmap graphics where each pixel is treated separately, and vector graphics where the lines on the drawing are created mathematically. Different software packages create the graphics in different ways for instance Paintbrush creates pictures in bitmap form while Draw uses vectors. The simple way of describing the difference is in sizing the drawing. If a drawing held as a bitmap is increased in size then each of the pixels is increased in size and hence becomes more obvious. If a drawing stored using vector graphics is increased in size the only thing that changes is the mathematical formulae for producing the lines, which will produce a picture of comparable quality whatever the size.
1.8 (d) Applications for which Common Packages are not appropriate
Common applications packages are those that have been designed to satisfy particular needs that are common to a number of different applications. There are many other examples where computers are necessary but where the use is so specialised that the software will need to be written (or at least tailored) for that particular use. Uses that would require such specialist software are legion, but would include many uses of control software. Robots used on production lines tend to be one-off machines, designed for that particular purpose, consequently, the software that would drive them would, similarly, be one-off. A stock control system in a warehouse would have standard modules, but would have other sections which would be for that warehousing system alone. The important consideration is how different from the standard design is the system for which we want the software, the further away from the standard, the more difficult it is to use standard software, and the more likelihood there is that the system will require software written specially for it.
Example Questions.
1. Discuss the reasons that a solicitors’ practice would have for choosing off-the –shelf software rather than custom written software if it was decided to change the word processor currently being used because it was perceived to be out of date. (4)
2. In the same scenario, State two reasons why custom made software might be more appropriate than off-the-shelf software. (2)
3. Describe how CAD/CAM can be used to produce prototype designs in a manufacturing process. (4)
4. A firm produces widgets for sale to the brewing industry.
A brewing company may come to the firm with a proposal for a widget to fit a particular container which will need to be produced by the firm which will then ship the finished product in batches and invoice the brewing company. Sometimes the sales team will be sent to try to persuade the brewing firm of the advantages of the company’s widgets.
Explain how the company can use commonly available software in the running of its business. (6)
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