More and more companies have joined the computing revolution and it is now very important to ensure compatibility between different manufacturers' hardware and software products. One way to do this is to maintain 'professional standards'.
Imagine buying a TV. You never think about whether the plug on the end of the TV's lead will actually fit into the wall socket and use the same voltage as in your house. You just assume it does!
Imagine a situation where you have 100 printer manufactures and a 100 computer manufacturers. There was a time about 30 to 40 years ago when a printer manufacturer made a printer for a specific computer manufacturer. If you had a computer and needed a printer, you had to go to just one maker of printers. These days, you probably don't even think about whether a printer will work with your computer. If you need a printer, you just go an buy one after reading the reviews, perhaps checking that it will work with your operating system. You don't ever think about whether the lead from the printer will connect to your computer, or whether they both use the same electrical signals, or use control signals that both the printer and computer can understand. It is the same for all hardware. They just plug into your computer and work. When you create a network of computers, they just connect together and work. Any software you buy also just loads up and works (as long as it is for the correct operating system).
This situation hasn't happened by accident.
These sets of rules are known as 'standards' although you may also see the word 'protocol' and all manufacturers work to the same standards or protocols. The big advantage to manufacturers is that their products are available to a much bigger set of customers. The customer wins, too, because they have a much bigger variety of products to choose from when they need some new hardware or software.
There are actually organisations set-up to define, maintain and develop standards. ANSI, IEEE and ISO are three of the largest organisations. For example, the IEEE are responsible for setting up many electrical standards. One of these is called the RS232C and is to do with the rules for communicating serially. If you ever buy a mouse for your computer, you can buy anyone you like and plug it in and it will work. This is because they all use the same set of rules to govern communication, the set of rules known as the RS232C.
You may have heard of some standards but not realised they were actually a standard, a set of rules. Some common ones include:
There are thousands of standards that cover a wide range of hardware and software. Standards ensure manufacturers can reach as many customers as possible and ensure customers have as much choice as possible when buying new equipment. If companies produced products in the way that they wanted to, without regard to anyone else's products, communication between computers and the setting up of networks like the Internet would not be possible - you wouldn't be able to transfer data between devices.
Computer systems are complex. If everyone involved in creating, using and maintaining a system did things their own way it would make it even more complicated. Professional standards can be formally agreed or “de facto” (“de” is pronounced “day”). De facto standards are when lots of people start working in a certain way and more people think it looks like a good idea and start doing it that way as well. Over time, this way of working becomes a standard, just because that is how most people do it. It is not a formally agreed standard where a committee of people sit down and agree how something should be done.
There are several approaches, or models, that define how a computer system is developed. Any new system starts with an idea or a need that must be analysed so a system can be designed and created. This development may take many months or years so there needs to be a way of splitting this down into logical steps and defining what each step will involve.
One such model is the “Waterfall Model”. This model defines definite steps that are completed one at a time to guide the process from beginning to end. Each step has specific outputs that lead into the next step. You can return to a previous stage if necessary but you then have to work back down through the following stages.
Another model is “Rapid Application Development” (RAD), where the client is much more involved in the process. This method starts with a prototype that is developed gradually into a full solution with customer feedback at each stage.
These are both standard approaches that teams of developers would be familiar with. Professionals in the industry would be familiar with these standard frameworks. They wouldn’t have to learn a new methodology every time they move to another job.
Q. Look up the various forms of system development and then produce a model of one. (A model can be an info-graphic or some form of flow diagram)
De facto standards in programming include the use of:
These are all considered “good practice”, the best way to do something. Using professional standards also means that programmers do not plagiarise other people’s work.
When developers write the programs they create something from their own mind. This is referred to as “intellectual property”. The Copyright, Designs and Patents Act protects people’s intellectual property rights. It protects the fact that they have worked hard to create something and stops somebody else just using it for their own gain. The "Federation Against Software Theft" (FAST) attempts to enforce the copyright laws and protect programmers’ rights.
However, some developers prefer not to protect their work in this way. Instead they actively collaborate with other programmers and create Open Source code, which others can use at no cost. The professional standards applied here are that any new code created from open source code is then also shared as open source code. (“Open Source” is discussed in more detail in Chapter 4, “Software”).
Professional standards apply to documentation as well as coding. A system developer will document the system using standard diagrams. These diagrams all use recognised sets of symbols.
While studying this GCSE you will use system flow charts to design algorithms. The symbols used in these diagrams are industry standard. You will also draw logic diagrams using standard symbols for the NOT, AND and OR logic gates.
These standards mean that system developers can:
Where the safety of people is concerned there needs to be more than just a de facto standard. There are laws that protect people and define standards for how computers systems should be used. For example, the Health & Safety at Work Act includes Display Screen Regulations. When developing a computer system the use of the system on a day-to-day basis must be considered. Developers design systems to meet health and safety regulations.