Home » Operating System – Scheduling Criteria

Operating System

Chapter 1: Introduction to Operating System 

— Definition of Operating System.

— Evolution of operating systems – simple batch systems, multi-programmed batch systems, time sharing systems.

— Functions of an operating system

— Characteristics of Operating System

— Single user and multi-user operating systems

Open-source and closed-source operating systems.

Important Questions with their Answers of “Introduction to operating system”

— MCQs and Fill in Blanks

— Short term Questions

— Long Term Questions


Chapter 2: Process Overview

Definition of process, process states, process life cycle,

Process Control Block (PCB),

Process Scheduling – Scheduling queues,

Schedulers (short term, medium term and long term).

Dispatcher.

Context Switch.

Important Questions with their Answers of “Process Overview”

— MCQs and Fill in blanks

Short term Questions

Long Term Questions


Chapter 3: CPU Scheduling

  • CPU Scheduler,
  • Preemptive and non-preemptive scheduling.
  • Scheduling criteria – CPU utilization, Throughput, Turnaround time, Waiting time, Response time.
  • Scheduling Algorithms: First-Come-First-Serve, Shortest-Job-First, Priority Scheduling, Round-Robin.

Important Questions with their Answers of “CPU Scheduling”

  • MCQs and Fill in blanks
  • Short term Questions
  • Long Term Questions

Operating System – Scheduling Criteria


There are several different criteria to consider when trying to select the “best” scheduling algorithm for a particular situation and environment, including:

    1. CPU utilization : To keep the CPU as busy as possible. It may range from 0 to 100%. In real time system, it suits range from 40% (for a lightly loaded system ) to 90% ( for heavily loaded system ).
    2. Throughput : It is the number of processes completed per unit time. This may range from 10 / second to 1 / hour depending on the specific processes.
    3. Turnaround time : It is the amount of time taken to execute a particular process, i.e. The interval from time of submission of the process to the time of completion of the process(Wall clock time).
    4. Waiting time : How much time processes spend in the ready queue waiting their turn to get on the CPU. Waiting time is the sum of period spends waiting in the ready queue.
    5. Response time : Amount of time it takes from when a request was submitted until the first response is produced. Remember, it is the time till the first response and not the completion of process execution(final response).

[In general, CPU utilization and Throughput are maximized and other factors are reduced for proper optimization.]


Leave a comment

Your email address will not be published. Required fields are marked *

‘Operating System’ Practical

  1. To install and configure MS Windows 7/8/10 on a computer
  2. To get familiar with general Windows commands – ECHO, CLS, DIR, TREE, MD, CD, TYPE, RD, DEL, MOVE, COPY , REN, ATTRIB, COLOR, DATE, TIME, ERASE, FIND, FC, MORE, CMD, PATH, SYSTEMINFO, SHUTDOWN, TASKLIST, TASKKILL, VER, VOL, CHKDSK
  3. To use wildcard characters for copying, moving, renaming, and deleting files and directories in a given hierarchical directory structure under Windows’s command prompt.
  4. To get familiar with windows control panel components.
  5. To use Windows backup and restore features.
  6. To get familiar with commonly used Windows PowerShell cmdlets like Get-ChildItem, GetContent, Get-Command, Get-Help, Clear-Host, Copy-Item, Move-Item, Remove-Item, Rename-Item, Get-Location, Set-Location, Write-Output, Get-Process, Stop-Process.
  7. To write scripts in Windows PowerShell to automate tasks.