A system is an arrangement of set of predefined set of rules in which all units assemble and work together according to a set of rules to organizing one or many tasks. It can also be defined as a system is a way of working, systematize or doing one or many tasks according to a prefixed plan or program. Let us examine a system with real time examples are as follows:
Consider a wrist watch either analog or digital. It is a time displaying system. As per analog wrist watch, parts include watch outer hardware, needles, battery, chassis, strap and designer dial. These all components are organized with a set of rules to show the real time every second and continuously update the time every second. This organized system updates the display using three needles after each second. Set of rules followed by watch are as follows;
- All needles move in clockwise direction only.
- A thin and long needle rotates every second such that it returns to same position after a minute.
- A long needle rotates every minute such that it returns to same position after an hour.
- A short needle rotates every hour such that it returns to same position after twelve hours.
- All three needles return to the same inclinations after twelve hours each day.
If any of its parts fails or starts work out of rules, then watch will stop working or displaying wrong time. So we can say, in a system, all its subcomponents depend on each other to perform correct job.
Consider another example of system i.e. washing machine. It is an automatic clothes-washing system. The essential hardware parts of a washing machine include a motor to rotate or spin, status display panel, the switches and dials for user-defined programming, its power supply and control unit, an inner water-level sensor, a solenoid valve for letting water in and another valve for letting water drain out. These parts put in order to wash clothes automatically according to a preinstalled program that preset by a user according to the cloth quality and dirt level. The system program is to wash the dirty clothes placed in a tank, which rotates or spins in pre-programmed steps and cover all stages to clear the dirt of cloths. It follows a set of rules.
Some of these set of rules are as follows:
- Follow the steps strictly in the following sequence.
Step I: Wash by spinning the motor according to a programmed period.
Step II: Rinse in fresh water after draining out the dirty water, and rinse a second time if the system is not programmed in water-saving mode.
Step III: After draining out the water completely, spin fast the motor for a programmed period for drying by centrifuging out water from the clothes.
Step IV: Show the wash-over status by a blinking display. Sound the alarm for a minute to signal that the wash cycle is complete.
- At each step, display the progress status of the system at displaying panel.
- In case of an interruption, execute only the remaining part of the program, starting from the position when the process was interrupted.
There can be no repetition from Step I unless the user resets the system by inserting another set of clothes and resets the program.