What is a Finite State Machine?

Computational Model

Before you dismiss the finite state machine as too ineffective to be considered as a computational model, keep in mind that since you may create as many states as you like, the machine can store arbitrarily lengthy histories. All you need is a state for each of the conceivable previous histories, and the state you discover the machine in will tell you not just where it is now, but also how it got there. 

Any device that stores the state of anything at a particular moment is referred to as a Finite State Machines. The state will change as a consequence of the inputs, delivering the final output for the modifications made.

Finite state machines (FSMs) are important for both understanding and controlling decision-making logic in computer systems. The outputs, as well as the future state, are current states and input functions in the FSM. This implies that the following state is mostly determined by the input value and strength, resulting in improved compound system performance. We need the history of previous inputs to decide the output, much like in sequential logic. As a result, FSM is extremely helpful in deciphering sequential logic responsibilities. Mealy machine and Moore machine are the two most common ways for arranging a sequential logic architecture.

It is used by programmers, mathematicians, engineers, and other professions. A set of buttons on a video game controller tied to a specified set of actions inside the game is a practical example of a finite state machine. When a user presses particular buttons, the system recognizes the commands and executes them.

Applications of Finite State Machines

FSMs are commonly employed in games; they are most known for their application in artificial intelligence, but they are also used in parsing text, customer input processing, and network protocols.

These have limited processing capacity, but they have the advantage of being quite easy to detect. As a result, software engineers and system designers typically utilize them to summarize the performance of a complex system.

Vending machines, video games, traffic lights, CPU controllers, text parsing, protocol analysis, voice recognition, language processing, and more applications use finite state machines.

Finite State Machine Benefits

  • It’s simple to go from a large abstract to code execution.
  • Finite state machines (FSMs) are adaptable.
  • Low CPU overhead Simple assessment of a state’s reachability

Finite State Machine Disadvantages

  • The sequence in which state transitions occur is set in stone.
  • It’s difficult to manage the development of large systems utilizing FSM if you don’t have any design ideas.
  • In certain fields, such as computer games, the predicted behavior of deterministic finite state machines may not be required.
  • Not all domains are eligible.

The following are some examples of operations with complicated logic:

  • Creating a schedule for a system’s activities or steps
  • Defining the logic for fault detection, isolation, and recovery
  • Observing how to change between several modes of functioning
  • State charts may be used to depict a finite state machine. Beyond standard finite state machines, state charts give extra features, such as:
  1. For large-scale systems, modeling hierarchical states
  2. To define complicated decision logic, flow graphs are included.
  3. Defining orthogonal states to describe parallelism in systems

Why Use Finite State Machines?

You may be asking why you should use a finite state machine to manage complicated state logic.

Debugging is rather simple 

A finite state system is relatively simple to debug. You can do this using a state machine visualization tool, which will save you a few hours of debugging time.

There are a limited amount of states

You already know how your state logic will appear and when you should transition from one state to another if you have a limited number of states.

Keep an eye out for unanticipated side effects

One of the most significant benefits of finite state machines is this. It’s related to the first tip, but by limiting the amount of states in your state logic, you’ll substantially lessen the number of unanticipated side effects.

Coverage of tests is high

It’s a lot easier to develop tests for your state logic when you have a limited number of states. You may eliminate a lot of needless tests and delete those side effect tests that we generally write if you don’t know how and where your state will change.

Modeling that can be seen

You may use a state machine visualization tool to design your state machine and see how your state logic would appear with finite state machines. It’s also easy to see faults or when you’re switching to the incorrect state.

To simplify a difficult task, a finite state machine may be built in software or hardware. All of the states considered in an FSM are listed in a finite list, and the abstract machine can only take on one of them at a moment. This method enables for the examination and testing of each input and output situation.

An FSM might be highly abstract, such as a business model represented by a picture, or very tangible, such as a vending machine or computer. Within a finite state machine, the number of potential combinations of these components is restricted. A state machine, on the other hand, may be ambiguous. A finite state machine allows for data points that do not fit neatly into clear, predefined categories.


Please enter your comment!
Please enter your name here