This document discusses instructions and procedures. It provides examples of a recipe for Indian tea and a procedure for a bank cashier. The recipe shows the step-by-step instructions for making Indian tea. The cashier procedure outlines the process a cashier follows when a customer withdraws money from their account, including greeting the customer, checking the account balance, updating records, and providing the cash. Written procedures are important when a task is complex or multiple people need to perform it consistently.

1. IIT Bombay
Computer Programming
Prof. Deepak B Phatak
Prof. Supratik Chakraborty
Department of Computer Science and Engineering
IIT Bombay
Session: Introduction
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Dr. Deepak B. Phatak & Dr. Supratik Chakraborty, IIT Bombay

2. IIT Bombay
Recap
• Computer is a machine
• It can operate only when a ‘program’ is given to it
• Program is a set of instructions
• Computer first reads and understand the entire program
• It then executes the instructions in specified order
Dr. Deepak B. Phatak & Dr. Supratik Chakraborty, IIT Bombay 2

3. IIT Bombay
Overview of This Lecture
• Instructions and Procedures
• A recipe for preparing Indian tea
• Procedure for a cashier in bank
Dr. Deepak B. Phatak & Dr. Supratik Chakraborty, IIT Bombay 3

4. IIT Bombay
Instructions, Procedures
• We often instruct people to do something
• Please get me a glass of water
• Please keep this book on the shelf
• Written Instructions are needed when
• A task is complex, needs many steps to be carried out
• Different people have to do the same task in exactly the same way
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Dr. Deepak B. Phatak & Dr. Supratik Chakraborty, IIT Bombay

5. IIT Bombay
Recipe for preparing Indian Tea
• Take a cup of water in a vessel
• Add two teaspoons sugar, one teaspoon tea leaves, milk
• Boil for 3 minutes
• Strain into a tea kettle
• Serve in a cup
Dr. Deepak B. Phatak & Dr. Supratik Chakraborty, IIT Bombay 5

6. IIT Bombay
(Wrong) Recipe for preparing Indian Tea
• Take a cup of water in a vessel
• Boil for 3 minutes
• Add two teaspoons sugar, one teaspoon tea leaves, milk
• Strain into a tea kettle
• Serve in a cup
Dr. Deepak B. Phatak & Dr. Supratik Chakraborty, IIT Bombay 6

7. IIT Bombay
Quiz
You will serve (a) Good Indian Tea (b) Hot water
(c) Some funny looking mixture (d) None of these
Dr. Deepak B. Phatak & Dr. Supratik Chakraborty, IIT Bombay 7

8. IIT Bombay
Analysis of the Quiz answers
• Since the water was not boiled with all ingredients, you will
certainly not get the Good Indian Tea. (a) is wrong
• You did add ingredients just before straining, so you will not
have plain hot water definitely. (b) is wrong
• Some colour from tea leaves, and some sweetness from
Sugar will be added. (c) is correct
• Since (c) is correct, (d) is obviously incorrect
Dr. Deepak B. Phatak & Dr. Supratik Chakraborty, IIT Bombay 8

9. IIT Bombay
A Banking Procedure
• An Old Bank maintains account information in ‘Ledgers’
• Customer comes to withdraw money from account
• Presents a cheque or a withdrawal-slip
• Should be paid cash if balance is adequate
• Appropriate entries must be made in the ledger
• A written procedure is used by the cashier
Dr. Deepak B. Phatak & Dr. Supratik Chakraborty, IIT Bombay 9

10. IIT Bombay
A job-card for Bank Cashier
• Greet the customer and collect the instrument presented.
• Keep the instrument on your right, and keep a paperweight
on it.
• Check balance in Account ledger
• Write a 'debit' entry in the ledger, update balance amount
• Count cash, and hand it over to the customer.
• Thank the customer for banking with your bank.
Dr. Deepak B. Phatak & Dr. Supratik Chakraborty, IIT Bombay 10

11. IIT Bombay
Summary
• A written procedure
• Must be first fully read and understood
• Then all steps must be executed in the specified order
Dr. Deepak B. Phatak & Dr. Supratik Chakraborty, IIT Bombay 11