Operatsion tizimlar tushunchasi va

Kutish vaqti: xizmat ko'rsatish vaqti - kelish vaqti (Wait Time : Service Time - Arrival Time)

Har bir jarayonning kutish vaqti quyidagicha -

FCFS

Average Waiting Time = (0 + 7 + 11 + 13) / 4 = 7.75

Shortest-Job-First (SJF) algoritm

Process Waiting Time

P1 5

P2 0

P3 9

P4 2

Average Wait Time: (0+2+5+9) / 4 = 4

Non-Preemptive SJF

Average waiting time = (0 + 6 + 3 + 7)/4 = 4

Priority Scheduling (Non Preemptive)

Completion Time

Priority Scheduling (Non Preemptive)

Turn Around Time = Completion Time - Arrival Time   

Waiting Time = Turn Around Time - Burst Time   

Avg Waiting Time = (0+11+2+7+12+2+18)/7 = 52/7

Round Robin(RR) Scheduling – Har bir jarayon uchun aniq vaqt belgilanadi va shu vaqtda bajariladi

• FCFS algoritmining modifikatsiyasi bu "Dumaloq Robin" ("Dumaloq Robin" - AQShdagi bolalar karuselining bir turi) yoki qisqacha RR deb nomlangan algoritmdir. Aslida, bu xuddi shu algoritm, faqat oldindan rejalashtirish rejimida amalga oshiriladi.