As observations are added to an inspection they are given a defect, and attribute information about that defect. Based on the PACP/MACP system the program calculates the Grade of the damage (how bad the damage is) and the number of occurrences the damage represents (usually 1, but may be more if it is a continuous defect). The system then uses these grades and occurrences to calculate the pipe or structure's rating.
Below is an example of a Grading System Code Matrix that complies with NAASCO PACP/MACP standards and some examples of how the Ratings fields are calculated.
Sample Grading Matrix
This matrix represents the calculations performed automatically by the system based on the PACP/MACP code selected by the user in the Observations record.
Occurrences*
Ratings*
Grades*
Structural
O&M
Overall
Structural
O&M
Overall
1
1
3
4
1
3
4
2
3
5
8
6
10
16
3
2
4
6
6
12
18
4
5
0
5
20
0
20
5
3
2
5
15
10
25
Totals
14
14
28
48
35
83
* These are automatically calculated by the system on the Observation record in the Grade fields.
* These are automatically calculated by the system on the Observation record in the Number fields.
* These are automatically calculated by the system on the Condition Ratings tab in the Ratings.
Pipe Ratings (Found on the Condition Ratings tab)
Pipes and Structures are graded based on the number and severity of defects observed.
Rating Indexes are the average grade of a type of defect found in the inspection. These calculations are based on the pipe ratings and # of occurrences. They are calculated by:
Rating Index Structural = Total Structural Rating/Total Structural Occurrences
Rating Index O&M = Total O&M Rating/Total O&M Occurrences
Rating Index Total = Total Rating/Total Occurrences
Example