Flow charts are diagrams that represent a sequence of steps to solve a problem. They use standard symbols to visually depict the logic and processes within a program or system. Flow charts facilitate communication between programmers and non-technical stakeholders. Guidelines for effective flow charts include using a logical structure, clear symbols, and ensuring the chart has a defined start and end. Pseudocode and structured English are additional tools to represent programming logic at a higher level before implementation in a specific coding language.

1. Flow Charts

2. Flow Charts
•A diagrammatic representation that illustrates the
sequence of operations to be performed to get the solution
of a problem.
• Generally drawn in the early stages of formulating
computer solutions.
• Facilitate communication between programmers and
business people.
• Play a vital role in the programming of a problem and are
quite helpful in understanding the logic of complicated and
lengthy problems.
• Once the flowchart is drawn, it becomes easy to write the
program in any high level language.
• Must for the better documentation of a complex program.

3. Flow Charts
A flow chart can be used to:
• Define and analyse processes.
• Build a step-by-step picture of the process
for analysis, discussion, or communication.
• Define, standardise or find areas for
improvement in a process.

4. Flow Charts
Symbols for drawing a flowchart:
Start or End of the program

5. Flow Charts
Symbols for drawing a flowchart:
Computational Steps or Processing Function
of a program

6. Flow Charts
Symbols for drawing a flowchart:
Input or output operation

7. Flow Charts
Symbols for drawing a flowchart:
Decision Making and Branching

8. Flow Charts
Symbols for drawing a flowchart:
Connector or joining of two parts of program

9. Flow Charts
Symbols for drawing a flowchart:
Magnetic Tape

10. Flow Charts
Symbols for drawing a flowchart:
Magnetic Disk

11. Flow Charts
Symbols for drawing a flowchart:
Off-page connector

12. Flow Charts
Symbols for drawing a flowchart:
Flow lines

13. Flow Charts
Symbols for drawing a flowchart:
Annotation (foot note)

14. Flow Charts
Symbols for drawing a flowchart:
Display

15. Flow Charts
Guidelines in flowcharting -
• In drawing a proper flowchart, all necessary
requirements should be listed out in logical order.
• The flowchart should be clear, neat and easy to
follow. There should not be any room for
ambiguity in understanding the flowchart.
• The usual direction of the flow of a procedure or
system is from left to right or top to bottom.

16. Flow Charts
…Guidelines in flowcharting -
• Only one flow line should come out from a
process symbol.
OR

17. Flow Charts
…Guidelines in flowcharting -
• Only one flow line should enter a decision
symbol, but two or three flow lines, one for
each possible answer, should leave the
decision symbol.

18. Flow Charts
…Guidelines in flowcharting –
Only one flow line is used in conjunction
with terminal symbol.

19. Flow Charts
…Guidelines in flowcharting –
Write within standard symbols briefly. As
necessary, you can use the annotation
symbol to describe data or computational
steps more clearly.
This is confidential data

20. Flow Charts
…Guidelines in flowcharting –
• In case of complex flowchart, it is better to use
connector symbols to reduce the number of flow
lines. Avoid the intersection of flow lines.
• Ensure that the flowchart has a logical start and
finish.
• It is useful to test the validity of the flowchart by
passing through it with a simple test data.

21. Flow Charts
Advantages Of Using Flowcharts :
• Effective communication
• Effective analysis
• Proper documentation
• Efficient Coding
• Proper Debugging
• Efficient Program Maintenance

22. Flow Charts
Limitations of using Flowcharts :
• Complex logic: Sometimes, the program
logic is quite complicated.
• Alterations and Modifications:
Alterations may require re-drawing
completely.
• Reproduction: As the flowchart symbols
cannot be typed, reproduction of flowchart
becomes a problem.

23. Flow Charts
Example 1.
Draw a flowchart to find the sum of first 50 natural numbers.

25. Flow Charts
Example 2
Draw a flowchart to find the largest of three
numbers A,B and C.

27. Flow Charts
Example 3
Draw a flowchart for computing factorial of a
given number

29. Assignment
Fill in the blanks-
2. A program flowchart indicates the_________ to be performed and
the __________ in which they occur.
3. A program flowchart is generally read from _____________ to
________________
4. Flowcharting symbols are connected together by means of
___________________
5. A decision symbol may be used in determining the ____________ or
___________ of two data items.
6. __________ are used to join remote portions of a flowchart
7. ____________ connectors are used when a flowchart ends on one
page and begins again on other page
8. A ________ symbol is used at the beginning and end of a flowchart.
9. The flowchart is one of the best ways of ________ a program..
10. To construct a flowchart, one must adhere to prescribed symbols
provided by the __________ .
11. The program uses a ____________ to aid it in drawing flowchart
symbols.

30. Answers
• Operations, sequence
• Top, down
• Flow line
• Equality, inequality
• connectors
• Off -page
• Terminal
• documenting
• ANSI (American National Standards Institute)
• Flowcharting template

31. Structured English

32. Structured English
• Structured English is a tool used to represent
process logic.
• Syntax rules are not very strict & an English
statement is used to specify an action.
• The main aim is to allow easy readability, which
helps in documentation.
Two building blocks of Structured English:
6. Structured logic or instructions organized into
nested or grouped procedures
7. Simple English statements such as add, multiply,
move

33. Structured English
Four conventions to follow when using Structured
English:
• Express all logic in terms of sequential structures,
decision structures, or iterations.
• Use upper case for keywords such as: IF, THEN,
ELSE, DO, DO WHILE, DO UNTIL, PERFORM
• Indent blocks of statements to show their
hierarchy (nesting) clearly.
• When words or phrases have been defined,
underline those words or phrases to indicate that
they have a specialised, reserved meaning.

34. The Flow of Structured English
Plain Structured Pseudocode Programs
English English
User Analyst Programmer

35. …Structured English
The conventions are used in writing structured
English:
• Imperative Sentences: Store the data in
database.
• Arithmetic & Relational Operations :
Common symbols of mathematics are used
in structured English such as- + for add, - for
subtraction etc. and =, >=, != etc. are used
for relational operations.

36. …Structured English
3. Decision Structures: If Then Else, Select
Case
4. Repetion: Loops
There are various forms in which structured
english can be implemented to solve the
problem. e.g. Algorithm, Flowchart,
pseudocode.

37. …Structured English

38. Writing Structured English
Repetition Conditions
IF … THEN …
DO
statements …
statements … ELSE
UNTIL end-condition statements …
END IF
or or
SELECT
CASE 1 (conditions)
DO WHILE
statements …
statements … CASE 2 …
END DO statements …
END SELECT

39. Pseudocode

40. Pseudocode
• An outline of a program, written in a
form that can easily be converted into
real programming statements.
• Pseudocode cannot be compiled nor
executed, and there are no real
formatting or syntax rules.

41. …Pseudocode
• It enables the programmer to
concentrate on the algorithms without
worrying about all the syntactic details
of a particular programming language.
• Flowcharts can be thought of as a
graphical form of pseudocode.

42. Example of Pseudocode
Regular code (written in PHP):
<?php
if (is_valid($cc_number))
{ execute_transaction($cc_number, $order); }
else { show_failure(); }
?>
Pseudocode:
if credit card number is valid
execute transaction based on number and
order
else show a generic failure message
end if