As an introduction to process control, there are four main elements of a process that are used as steps to calibrate and maintain the state of a process.
The process consists of equipment as an assembly and its operational material. Processes are operations made in sequences and the whole process is modeled into a set a variables. As an example, a computer uses processes to maximize the performance of the computer.
A measurement is taken of certain parts of the process so that the state of the process can be calibrated and the information can be used for calculations. As an example, an oil refinery has many stages in its operation and all stages need to be measured.
An evaluation is made from calculating the measurement to determine if any adjustments need to made to the variables of the process. As an example, a chemical plant has to blend specific mixes of chemicals in the correct sequence. These mixes have to be fine tuned to meet specification and one batch of chemical may react a little different from another batch so the balance needs to be maintained.
The control is the adjustment made to a particular part of the process to optimize the system to its best state. As an example, adjustments have to be made to a heating control system to maintain the optimal temperature.
The introduction to process control covers four stages: