Purchasing versus Retrofitting
The first step in a Buy-Quiet procurement process, Cooper explained, is planning the procurement. This means knowing the functional requirements for the object being purchased and the in situ noise-emission requirements. In NASA’s web-based Buy-Quiet Roadmap tool,11 the default procurement process requires formal comparison of products, considering the differences in both noise emission and cost. It also uses a procedure to calculate the cost of noise in order to estimate the net present value of long-term exposure to the noise generated by each product. This calculation enables the contracting officer to weigh the purchase price against the long-term cost associated with the product. This calculation would need to be customized for parks, for which lower-level noise is also problematic and for reasons other than hearing loss risk, Cooper acknowledged, but it could certainly be adapted.
Establishing baseline noise emission criteria is an important part of the process. Cooper cited the European Union (EU) machinery directive,12 based on best practices and what is technically achievable, as a good resource. If the product doesn’t appear there, 80 dBA sound level at one meter is NASA’s default assumption. Sometimes, an informed adjustment of the noise emission criterion is necessary. If equipment is sited outside, NASA uses a community noise checklist,13 which alerts the purchaser to any potential problems.
The more risk there is, Cooper said, the more complex the procurement process. Targeting procurement strategy for each purchase allows the maximum use of simpler procurement vehicles. If the purchase must go through the complete tradeoff process, a tradeoff analysis worksheet can be used to evaluate the net long-term cost of candidate products, enabling the contracting officer to make a selection based on all the relevant information. Using the worksheet to record the noise-level criterion, the number of employees exposed, the quoted sound power level for each item, and environmental characteristics, it is possible to compute the net cost of additional noise for up to three products at a time.
11 For more information, see http://buyquietroadmap.com/buy-quiet-purchasing/buy-quiet-process-roadmap/.
12 For more information, see http://ec.europa.eu/enterprise/sectors/mechanical/documents/legislation/machinery/index_en.htm.