Opportunity Management - Budget Spread Rule Calculation

The budget spread rule calculation applies the trapezium rule to compute the value of the budget to allocate it to each time phased period.

Formula = (Area of Trapeziums for Period) ÷ (Total Spread Rule Trapezium Area) × Budget

The Area of Trapeziums for Period may consist of a sum of multiple fractions of Spread Rule Trapeziums coalesced together to make one time-phased period. The number of trapeziums determines where each trapezium starts and ends in the Spread Rule for each time phased period.

Example:

NOTE: Currently only the GLPERIOD (G/L period) interval option can be used for opportunities, as the other options are related to the deprecated detailed time phased budgeting functionality. For more information, please refer to Job Costing - Create Budget Spread Rule.

The following breaks down the calculation of the amounts from Opportunity Management.

Potential Revenue: $100,000.00

Spread Rule Details:

X Axis Y Axis
1 0.22
2 0.34
3 0.34
4 0.1

The following is a Spread Rule Chart for reference of the use of trapeziums in the calculation.

Image of Spread Rule Chart.

Trapezium Area Formula = ((a + b) ÷ 2) × h

Area between 1 and 2:

a = 0.22 b = 0.34 h = 2-1 Area = 0.28

Area between 2 and 3:

a = 0.34 b = 0.34 h = 3-2 Area = 0.34

Area between 3 and 4:

a = 0.34 b = 0.10 h = 4-3 Area = 0.22

Total area: 0.28 + 0.34 + 0.22 = 0.84

The total area of the chart for this spread rule is 0.84.

Trapezium Per Period Formula

Trapezium Per Period = (Spread Rule Count - 1) ÷ Effective Number of Periods

Where:

Spread Rule Count = 4 (Number of X Axis from Spread Rule Detail)

Effective Number of Periods = 4 (from Opportunity: Service End Date - Service Start Date)

Trapezium Per Period = ( 4 - 1 ) ÷ 4 = 0.75

The number of trapeziums per period is 0.75.

Defining X-Axis for the Trapeziums

The following is the X axis considering trapezium per period (starting at 1) until we hit the final period:

1 + 0.75 = 1.75 1.75 + 0.75 = 2.5 2.50 + 0.75 = 3.25 3.25 + 0.75 = 4

The following is the X axis inherited from the spread rule:

1 2 3 4

The following is the X axis to be used to calculate trapeziums (combination of all the above):

1 1.75 2 2.5 3 3.25 4

Defining Y-Axis for the Trapeziums

The following shows the correspondent Y axis value for the X axis that comes from the budget spread detail:

X Y
1 0.22
1.75  
2 0.34
2.5  
3 0.34
3.25  
4 0.1

Intermediate values must be calculated:

X Difference between points (Y) Difference between current and prev X Proportion of the difference between Y Y
1       0.22
1.75 0.34 - 0.22 = 0.12 1.75 - 1 = 0.75 0.12 * 0.75 = 0.09 0.22 + 0.09 = 0.31
2       0.34
2.5 Same logic, but since Y is the same for 2 and 3, 2.5 will also be 0.34 (linear) 0.34
3       0.34
3.25 0.1 - 0.34 = -0.24 3.25 - 3 = 0.25 -0.24 * 0.25 = -0.06 0.34 + ( -0.06 ) = 0.28
4       0.1

Matrix of the edges (x1, x2, y1, y2) of all trapeziums and their area (calculated by the trapezium area formula):

  x1 y1 x2 y2 Area Period
t1 1 0.22 1.75 0.31 0.19875 First period (x1 = 1)
t2 1.75 0.31 2 0.34 0.08125 Second period (x2 = 2)
t3 2 0.34 2.5 0.34 0.17 Second period (x1 = 2)
t4 2.5 0.34 3 0.34 0.17 Third period (x2 = 3)
t5 3 0.34 3.25 0.28 0.0775 Third period (x1 = 3)
t6 - - - - - Fourth period is not calculated (it will be considered the remaining amount)

Calculate the percentage of each sub-trapezium over the total trapezium area (0.84) and multiply by the budget. These are the final amounts that are seen in the opportunity:

Period 1: (0.19875 / 0.84) * 100,000.00 = 23,660.71 (23.66%)

Period 2: (0.08125 / 0.84) * 100,000.00 = 9675.61 + ((0.17 / 0.84) * 100,000.00) = 29,910.71 (29.91%)

Period 3: (0.17 / 0.84) * 100,000.00 = 20238.09 + ((0.0775 / 0.84) * 100,000.00) = 29,464.29 (29.46%)

Period 4: 100,000.00 - (23660.71 + 29910.71 + 29464.29) = 16,964.29 (16.96%)