Calculate Total Cost And
Incremental Costs
Principles of Cost Analysis and
Management
© Dale R. Geiger 2011
1
What if?
• Relationship between cost and unit of output
is neither fixed nor variable?
• There are multiple elements that affect the
cost of an output?
• A different type of cost relationship is relevant
to the decision at hand?
© Dale R. Geiger 2011
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Terminal Learning Objective
• Task: Calculate Total Cost And Incremental Costs Given
Various Production Volumes
• Condition: You are a cost advisor technician with access to
all regulations/course handouts, and awareness of
Operational Environment (OE)/Contemporary Operational
Environment (COE)
• Standard: With at least 80% accuracy:
•
•
•
•
Describe multivariate (mixed) and incremental costs
Express total multivariate cost in an equation
Graph total multivariate cost over a relevant range
Express incremental cost in an equation
© Dale R. Geiger 2011
3
Cost Definitions
• Mixed Costs - A combination of fixed and
variable costs
Total Cost =
Variable Cost + Fixed Cost
• Also known as multivariate costs
© Dale R. Geiger 2011
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Multivariate Cost Expressions
• Variable component:
• Variable $Cost per Unit * # Units
-Plus• Fixed component:
• Sum of relevant costs that remain the same
regardless of units of output
© Dale R. Geiger 2011
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Multivariate Cost Example
• Relevant cost of transporting a unit for onlocation training is $350,000.
• Cost of training operations on-location runs
$20,000 per day.
• What is the unit of output?
• Days of training
© Dale R. Geiger 2011
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Multivariate Cost Example
• Relevant cost of transporting a unit for onlocation training is $350,000.
• Cost of training operations on-location runs
$20,000 per day.
• What is the unit of output?
• Days of training
© Dale R. Geiger 2011
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Multivariate Cost Example
• Relevant cost of transporting a unit for onlocation training is $350,000.
• Cost of training operations on-location runs
$20,000 per day.
• What is the cost expression for Fixed cost?
• Fixed cost = $350,000
© Dale R. Geiger 2011
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Multivariate Cost Example
• Relevant cost of transporting a unit for onlocation training is $350,000.
• Cost of training operations on-location runs
$20,000 per day.
• What is the cost expression for Fixed cost?
• Fixed cost = $350,000
© Dale R. Geiger 2011
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Multivariate Cost Example
• Relevant cost of transporting a unit for onlocation training is $350,000.
• Cost of training operations on-location runs
$20,000 per day.
• What is the cost expression for Variable Cost?
• Variable cost = $20,000/day * # of days
© Dale R. Geiger 2011
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Multivariate Cost Example
• Relevant cost of transporting a unit for onlocation training is $350,000.
• Cost of training operations on-location runs
$20,000 per day.
• What is the cost expression for Variable Cost?
• Variable cost = $20,000 per day * # of days
© Dale R. Geiger 2011
11
Multivariate Cost Example
• Relevant cost of transporting a unit for onlocation training is $350,000.
• Cost of training operations on-location runs
$20,000 per day.
• What is the cost expression for Total Cost of
on-location training?
© Dale R. Geiger 2011
12
Multivariate Cost Example
• Relevant cost of transporting a unit for onlocation training is $350,000.
• Cost of training operations on-location runs
$20,000 per day.
• What is the cost expression for Total Cost of
on-location training?
• Total Cost = Variable cost + Fixed Cost
• Total Cost = $20,000 per day * #days +
$350,000
© Dale R. Geiger 2011
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Graph of Mixed Cost
$K 700
600
500
400
$350K
Fixed Cost
300
200
100
0
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15
X Axis = Number of Days
As Number of Days increases, Fixed Cost does not change
© Dale R. Geiger 2011
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Graph of Mixed Cost
$K 700
Variable cost
for 10 days =
$20K per day * 10 days
= $200K
600
500
400
Fixed Cost
Variable Cost
300
200
100
0
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15
X Axis = Number of Days
As Number of Days increases, Variable Cost increases
© Dale R. Geiger 2011
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Graph of Mixed Cost
Total cost for 10 days =
$20K per day * 10 days +
$350K
or $550K
$K 700
600
$550K
500
400
Fixed Cost
Variable Cost
Total Cost
300
200
100
0
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15
X Axis = Number of Days
As Number of Days increases, both Variable Cost and Total Cost increase 16
© Dale R. Geiger 2011
Questions
• What is the cost expression for Cost per Day?
• How would the graph of Cost per Day look?
• It should be a downward sloping curve that will
level out above $20K
© Dale R. Geiger 2011
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Cost Definitions
• Semi-variable Cost - Costs that Increase as
Unit of Output increases, but not in Direct
Proportion
• Examples:
• Hours worked by an employee
• Miles driven
• Students in a course
© Dale R. Geiger 2011
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Semi-Variable Cost Example
• Sometimes the Variable Cost per unit
remains the same only for a Relevant Range
• Example: Employee Wages
• Employee’s base wage is $15 per hour
• If the employee works more than 40 hours in a
week we must pay time and a half
© Dale R. Geiger 2011
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Cost Expression for Semi Variable
• The cost expression for Total Wage Cost is:
1.5
Straight * Straight Time + Overtime *
*
Time Hours
$ per Hour
Hours
Straight Time
$ per Hour
© Dale R. Geiger 2011
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Cost Expression for Semi Variable
• If the total number of hours worked is 30 and
straight-time rate is $15 per hour then:
1.5
30
0
*
Straight * $15 per Hour + Overtime * Straight
Time
Time Hours
Hours
$ per Hour
= $450
© Dale R. Geiger 2011
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Cost Expression for Semi Variable
• If the total number of hours worked is 44 and
straight-time rate is $15 per hour then:
40
4
Straight * $15 per Hour + Overtime *
Time Hours
Hours
1.5
*
$15
per Hour
= $690
© Dale R. Geiger 2011
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Graph for Total Wage Cost
1000
800
600
400
200
0
0
3
6
9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60
X Axis = # of Hours Worked
As # Hours Worked increases, total Wage Cost increases, but not uniformly
© Dale R. Geiger 2011
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Graph for Wage Cost per Hour
25
20
15
10
5
This is known as a Step Function.
Cost per Hour for Hours 0-40 = $15
Cost per Hour for Hours 41-60 = $22.50
0
X Axis = # of Hours Worked
As # Hours Worked increases, Wage Cost per Hour remains the same for the relevant range
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© Dale R. Geiger 2011
Questions for Thought
• What about a volume discount?
• Units 1-20 cost $10 per unit
• Units 21-50 cost $9 per unit
• Units 51-100 cost $8 per unit
• How would you express this cost relationship
• In total? On a per-unit basis?
• How would the graph of each look?
• What is the cost of 16 units? Of 67 units?
© Dale R. Geiger 2011
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