Definition
FCFS is a scheduling algorithm that enables networks and operating systems to execute processes, tasks, and requests according to the order they are added to the queue efficiently and automatically.
Because of their simplicity, FCFS algorithms handle requests and tasks predictably. FCFS is one of the most autonomous and productive scheduling algorithms because it doesn’t waste time ranking requests and tasks by complexity or priority.
Examples of FCFS Scheduling
- Purchasing a movie ticket at a counter: When buying a movie ticket, customers are served in the order in which they appear in the queue. The first person in line buys the ticket, followed by the next person in line, and so forth.
- Customer service lines: Most service-oriented organizations, such as restaurants, hospitals, and banks, rely on FCFS to serve their customers.
Pros and Cons of FCFS
Pros
- Simplicity: The FCFS algorithm uses the simple principle of a first come, first serve sequence.
- User-friendly: Designing the algorithm is easy, straightforward, and requires less time and labor.
- Easy to implement: Due to their simple design, FCFSs are easy to implement into existing systems.
Cons
- Long waiting time: The FCFS algorithm is non-preemptive, so a process with a higher burst time in an FCFS queue blocks tasks with a lower burst time, resulting in a longer waiting time.
- Lower device usage: FCFS is wasteful because orders are handled in chronological order, causing a backlog.
- CPU over I/O: The algorithm prioritizes CPU over I/O, which may discourage I/O users.
