1. Flowcharts

2. What Is a Flowchart?
A diagrammatic representation that illustrates the sequence of operations to be performed to get the solution of a problem.
Facilitates communication and understanding
ANSI (American National Standards Institute) has defined the symbols and their use
Usually drawn in the early stages of formulating computer solutions.
helpful in understanding the logic of problems.
Makes if easier to write the program/problem it represents
In some venues a flowchart is a must for the better documentation of a complex program or problem.

3. Standard Symbols used in a Flowchart
Process symbol
Indicates when a computational step occurs
Terminal
The start or end of the chart
Input or output operation
Is used whenever data (information that is manipulated or used to manipulate) is added to the program Or Or

4. Standard Symbols used in a Flowchart
Condition or Decision
Decision making and branching of code
Connector
Indicates where a separate part of the code is being addressed
Common label is placed within the symbol
Flow lines
Indicate the flow of logic

5. Standard Symbols used in a Flowchart
Preparation
Setting up initial values
Off-page connectors
Used to connect different parts across pages.
Again a common symbol followed by the page it is continued on…. or continued from will identify the different parts (

6. Guidelines when drawing a Flowchart
All steps must be listed in order
Clear, neat and easy to follow – should have no ambiguities (super clear)
Flow travels top down, or left right
Process symbols can only have 1 flow line out.

7. Guidelines continued
Only on flow line should enter a decision symbol, but 2 or 3 flow lines may leave
Only on flow line with a terminal symbol
If the flowchart becomes complex use connector symbols to reduce the number of flow lines (place the section in another space)
Yes No

8. Guidelines continued
Avoid intersecting flow lines to be more effective and clear
Make sure your flowchart has a logical start and finish
To test your flowchart, use a simple example and step it through the steps of your algorithm. This should catch any errors in logic.

9. Advantages of Flowcharts
For simple problems, they are a better way to communicate the logic of problem because it is a diagram.
Helps in the analysis of a problem
Can serve as a good way to document a problem
Helps a programmer to code more efficiently and quickly
Helps in the debugging process of a problem
Helps with identifying where new features of fixes (maintenance) of a program can take place

10. Limitations of a Flowchart
Complex problems cannot be solved with flowcharts because the flowcharts become clumsy and complicated (too hard to follow)
Any alterations require a total redraw in most cases
Reproducing flowchart symbols can be a pain
The detail of the flowchart can mask the real problem we are solving. (Lost in the detail)

11. Example – making tea

12. Make a flowchart that sums all the numbers from 1 to 10

13. Make a flowchart that sums all the numbers from 1 to 10

14. Make a Flowchart describing a person getting woken by alarm and using the snooze button before getting out of bed

15. Make a Flowchart describing a person getting woken by alarm and using the snooze button before getting out of bed

16. Reference locations http://www.nos.org/htm/basic2.htm