1. Creating Flowcharts Principles Of Engineering
© 2012 Project Lead The Way, Inc.

2. Name of PowerPoint
CIM
Name of Lesson
Definition
A flowchart is a schematic representation of an algorithm or a process.
A schematic is a diagram that uses special symbols in place of actual pictures. In a wiring schematic, for example, a squiggly line is used to represent a resistor.
An algorithm is a series of steps that tell how to complete a task. For example, an algorithm for reducing a mathematical expression could be: First, perform the operations contained within the parentheses. Then calculate the exponent, if preset. Next, multiply and divide from left to right. Finally, add and subtract from left to right. Here we have a simple flowchart that might show the steps in feeding a dog.
Project Lead The Way, Inc.
Copyright 2008

3. Parts of a Flowchart Start/end Input/output Process Arrows Display
Name of PowerPoint
CIM
Name of Lesson
Parts of a Flowchart
Start/end
Input/output
Process
Arrows
Display
Decision
Project Lead The Way, Inc.
Copyright 2008

4. Start/End Shape is a rounded rectangle
Name of PowerPoint
CIM
Name of Lesson
Start/End
Shape is a rounded rectangle
Start is required of all flow charts
Some flow charts may not have an END
The design process is iterative; that is, it may repeat steps, or it may backtrack several steps.
Project Lead The Way, Inc.
Copyright 2008

5. Process Shape is rectangular
Name of PowerPoint
CIM
Name of Lesson
Process
Shape is rectangular
Process involves the action or the “verb” part of the flowchart
Examples include
Add 1
Turn the motor on
Turn the light off
Rotate the part
Project Lead The Way, Inc.
Copyright 2008

6. Input/Output Shape is a parallelogram
Name of PowerPoint
CIM
Name of Lesson
Input/Output
Shape is a parallelogram
Indicates that manual operation is needed
Examples include
Type in the weight
Check the balance
Time the operation
Project Lead The Way, Inc.
Copyright 2008

7. Decision Shape is a rhombus Outcome is either yes or no
Name of PowerPoint
CIM
Name of Lesson
Decision
Shape is a rhombus
Outcome is either yes or no
Examples include
Is this number larger than 10?
Does the weight meet specifications?
Has the count been reached?
From geometry you may remember that a rhombus is a quadrilateral with all four sides congruent. It is different from a square in that the angles are not all right angles. Some refer to this block as a diamond because it has been rotated 45o, whereas most rhombi lie on their bases.
Project Lead The Way, Inc.
Copyright 2008

8. Arrows Arrows indicate the flow of the chart.
Name of PowerPoint
CIM
Name of Lesson
Arrows
Arrows indicate the flow of the chart.
Arrows are drawn from the output of one block to the input of another.
Only one arrow can represent outputs.
Multiple arrows may represent inputs.
Project Lead The Way, Inc.
Copyright 2008

9. Example COUNT... Count from 1 to 9 by odd numbers.
Name of PowerPoint
CIM
Name of Lesson
Example
Count from 1 to 9 by odd numbers.
Before attempting to draw the flowchart, determine what you want the output to be.
What is the first block (always)?
Answers on next slide.
COUNT...
Project Lead The Way, Inc.
Copyright 2008

10. Name of PowerPoint
CIM
Name of Lesson
Step 1
The output will be 1, 3, 5, 7, 9.
The Start block is always first.
START
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Copyright 2008

11. Step 2 The program begins with the number 1. START INPUT 1
Name of PowerPoint
CIM
Name of Lesson
Step 2
The program begins with the number 1.
START
INPUT 1
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Copyright 2008

12. Step 4 Now that there is a number, the program will state the number.
Name of PowerPoint
CIM
Name of Lesson
Step 4
Now that there is a number, the program will state the number.
START
INPUT 1
SAY NUMBER
Project Lead The Way, Inc.
Copyright 2008

13. Name of PowerPoint
CIM
Name of Lesson
Step 3
The number 2 will be added to 1 so that the program will continue to count by odd numbers.
START
INPUT 1
SAY NUMBER
To move from 1 to 3, we would add 2. This is a crucial step because it determines the pattern for the rest of the process.
ADD 2
Project Lead The Way, Inc.
Copyright 2008

14. Name of PowerPoint
CIM
Name of Lesson
Step 4
START
INPUT 1
SAY NUMBER
Add a decision block so that the program will continue counting until the value is greater than 9.
ADD 2
Is number >9? NO
Project Lead The Way, Inc.
Copyright 2008

15. Step 5 Once the number is greater than 9, the program ends. START END
Name of PowerPoint
CIM
Name of Lesson
Step 5
START
INPUT 1
SAY NUMBER
Once the number is greater than 9, the program ends.
ADD 2
Is number >9? NO
If yes, the flow chart will stop. If no, it will flow back to the arrow above, which is Add 2. Does it matter which branch we call Yes and which one we call No? (Yes, for the flow.) If it does matter, can we make it work? (Yes, we can make it work either way.) What would the flow chart look like? (Either switch the places for Yes and No on the Decision block and change where the arrows lead, OR simply switch where the arrows lead. Sometimes this second choice is not a good one, even though it sounds easier, because it makes the flow chart look sloppy. In this example the END block is right below Yes. If END matches up with No, the flowchart would look messy.)
YES
END
Project Lead The Way, Inc.
Copyright 2008

16. Your Turn Create a flow chart that shows how to pour a glass of milk.
Name of PowerPoint
CIM
Name of Lesson
Your Turn
Create a flow chart that shows how to pour a glass of milk.
How is this problem different from the one before it? (This problem has many solutions.) Does it matter what your “Start” represents? (Yes, it will determine how you proceed. Your Start may require a check to see if you even have any milk, or it may begin with a direction to go to the store to buy milk.) What sort of assumptions do you make when you create a flowchart like this one? (You must decide where to start and how far you want to take it. Does the glass size matter? Does it matter where the person using the flowchart is standing when beginning? Do you want the end to come with the milk poured, or put away, or with the glass washed?)
Project Lead The Way, Inc.
Copyright 2008