Previous Chapter: NASA Dryden Flight Research Center Statistical Model
Suggested Citation: "Simplified BMAR Algorithm." National Research Council. 2001. Deferred Maintenance Reporting for Federal Facilities: Meeting the Requirements of Federal Accounting Standards Advisory Board Standard Number 6, as Amended. Washington, DC: The National Academies Press. doi: 10.17226/10095.
BMAR Algorithm

For every condition code a statistical weight is assigned based on random sampling. BMAR is equal to the sum of all equipment replacement costs multiplied by respective statistical weights.

BMAR=SUMj=1,5{SUMk=1,n{(CCF)j (RC)k}}

where: SUM is the summation function

CCF is the condition code factor (weight)

RC is the replacement cost

n = the total pieces of equipment for the condition code

Example Calculation of BMAR

Parameters: Assume a 300 item inventory; total replacement cost = $1,000,000; 4 item statistical sample.

Inventory #

Repair Cost

Replace Cost

Repair/Replace

7

100

10000

0.10

43

500

2000

0.25

115

300

4000

0.075

267

200

3000

0.066

Total replacement cost = $1,000,000

Condition Code Factor (CCF)= (0.1+0.25+0.075+0.066)/4=0.123

BMAR = (Total Replacement Cost)(CCF)= ($1,000,000)(0.123)=$123,000

NASA Simplified BMAR Model Using Real Property Data

The Dryden Flight Research Center has proposed a less complex model that does not require the use of a CMMS. Instead, it uses real property records common to all agencies. In this model, statistical sampling by facility type is used to determine the backlog of maintenance and repair. The backlog is determined by using a random sample of facilities in an agency's inventory and concentrating on a specified number of major systems, for example, structural, mechanical, and electrical. A weighted average is calculated for the net condition code, and the backlog is then assumed to be an exponential function of condition.

Simplified BMAR Algorithm

A statistical weight (CCF) is assigned based on random facility sampling. BMAR is equal to the sum of all facility replacement costs multiplied by the CCF.

BMAR={SUM k=1,n{(CCF) (CRV)k}

where: SUM is the summation function

Suggested Citation: "Simplified BMAR Algorithm." National Research Council. 2001. Deferred Maintenance Reporting for Federal Facilities: Meeting the Requirements of Federal Accounting Standards Advisory Board Standard Number 6, as Amended. Washington, DC: The National Academies Press. doi: 10.17226/10095.
Page 36
Next Chapter: Sample Calculation
Subscribe to Email from the National Academies
Keep up with all of the activities, publications, and events by subscribing to free updates by email.