What is the input process output model?

Data pro­cessing by computers or humans generally always follow the same sequence of stages: input, process and output (IPO). For this reason, the uni­ver­sally ap­plic­able IPO model is used in con­nec­tion with elec­tron­ic data pro­cessing. This also describes how computers function and operate.

What does the IPO model stand for?

The ab­bre­vi­ation ‘IPO’ is derived from the first letters of the words input, process and output:

1. Data is entered into pro­cessing units such as computers via input devices.
2. The data is processed according to pre­defined rules.
3. The processed data is displayed or output for users via various display or output devices.

The IPO model (sometimes knows as the IPO principle) describes the basic sequence of data pro­cessing and is regarded as an important basic pattern of EDP (Elec­tron­ic Data Pro­cessing). It does not matter whether the data is entered and processed by a computer or a human being. What is important is that the sequence for data pro­cessing remains the same. The IPO approach describes systems hol­ist­ic­ally as well as in parts. This means, for example, that a computer system first receives an input as a whole in order to process and output it in certain subareas of the system.

Why is the IPO model important?

Some may claim that the IPO model only describes what is already obvious. However, from a hardware and software de­vel­op­ment point of view, it is actually an important guideline. Only when the basic struc­tures of data pro­cessing cor­res­pond to the IPO model can it be assumed that input, process and output will be aligned to the desired mode of operation and no errors will occur.

In the following section, we’ll explain the sig­ni­fic­ance of the input, process and output model when it comes to hardware and software de­vel­op­ment:

Hardware

When de­vel­op­ing hardware, it must be clear which types of input signals the hardware should process. This is because the type of input signal de­term­ines which devices should be used for the input. The pro­cessing units needed are de­term­ined by how the pro­cessing should take place. The output devices used for the display or output depend on which actions are desired after the input.

Software

Software de­vel­op­ment also follows the IPO model. A program must be developed in advance with the input data in mind, in order to un­der­stand what is supposed to be done with the data. For example, in text or system programs, input, process, and output occur dif­fer­ently than in a design program or mul­ti­me­dia player. Depending on the input command, other units and output devices may need to be con­trolled. Pro­gram­ming paradigms and al­gorithms that are used in the de­vel­op­ment of software also rely on the IPO model.

How does input, process and output work?

As a universal guideline, the sequence and flow of data pro­cessing according to the IPO model can be explained like this:

Input (‘I’)

The input of data takes place in the form of a command or in­struc­tion given to the device or system. Input can be made via various input devices as required. These include:

• Computer keyboard
• Mouse
• Mi­cro­phone
• Touch­screen
• Touchpad
• Scanner
• Webcam
• Eye control
• On-screen keyboard
• Game con­trol­ler/joystick

Input devices are used to enter commands and data in various forms and ways. This includes letters, numbers, clicks, symbols, Windows shortcuts, voice commands, touch commands, visual data or scans of documents. Depending on the device and program you are working with, the data is processed dif­fer­ently.

Process (‘P’)

The pro­cessing or cal­cu­la­tion of input data is performed by units designed for this purpose. The most important of these are the processor (CPU), the RAM (main memory) and the graphics card (GPU). The most important unit for pro­cessing is the branch of the processor and RAM. Here the output is cal­cu­lated, and the input command is im­ple­men­ted, while data is stored and cached sim­ul­tan­eously.

Hard disks, RAM, cloud storage, DVDs and USB sticks are used for storage. It should be noted, however, that memory is not con­sidered a pro­cessing unit, but has a separate position in the IPO sequence. The algorithm de­term­ines which output devices are con­trolled and which data is processed.

Output (‘O’)

In order to output the processed data as required, computers or elec­tron­ic devices have cor­res­pond­ing output units. These ensure that processed data is displayed on a monitor/screen or output via, for example, speakers, a printer, projector or head­phones. This means that the movement of the mouse pointer on the monitor is just as much an output according to the input, process, and output model as letters being typed on the screen or documents being printed.

When is the IPO model used?

Since it is a universal guideline, the IPO model can basically be applied to any situation where input signals should lead to results. The best example are the ‘input devices’ of the human body, be it eyes, ears, nose, mouth or skin. On the one hand, we take in external signals passively via smells, sounds and the visible en­vir­on­ment, and on the other hand, we take them in actively by reading, watching a film, listening to music or enjoying our favourite food. Signals are processed and results produced via our senses and pro­cessing units such as the brain, organs, bones, muscles and tendons. These include images, colours, tastes, meanings, a smell or con­ver­sa­tions.

When de­vel­op­ing func­tion­al hardware and software, the IPO model plays a decisive role, es­pe­cially from the point of view of troubleshoot­ing and per­form­ance op­tim­isa­tion. The model specifies test sequences that indicate when an input signal does not result in the desired output. This means that errors or in­com­pat­ib­il­it­ies in input devices or output devices as well as de­fi­cien­cies in pro­cessing units can be iden­ti­fied and rectified. In this way it can also be de­term­ined, for example, whether data pro­cessing in pro­cessors is to take place sim­ul­tan­eously over several cores by mul­ti­th­read­ing or hy­per­thread­ing and which areas of the kernel are used.

Examples of the IPO model from data pro­cessing

Examples of the IPO model can be found in basically every data input on your PC, smart­phone, tablet, printer, scanner or Bluetooth device. For example, if you enter a word via the keyboard, the signals from the keyboard are displayed on the monitor as a word via pro­cessing units such as the CPU, RAM and word pro­cessors. In turn, if you click on a video link, the browser calls up the cor­res­pond­ing website, the computer’s audio devices start audio playback, and the video is displayed on the monitor.

The same applies when printing a document. You select the format, the printing colour and the number of copies, then start the printing process and at the end, you hold the printed documents in your hand. Every machine that fulfills a certain function is basically applying the IPO model. This could be an ATM for dis­pens­ing cash or dis­play­ing your account balance, a scanner for scanning documents, a game console hooked up to a screen with game con­trol­lers or a music system with speakers.

Summary

The IPO model rep­res­ents an important guideline for guar­an­tee­ing seamless, efficient data pro­cessing. It ensures that errors between input and output are excluded or iden­ti­fied and makes it possible to make data pro­cessing processes as con­tinu­ous and resource efficient as possible.