Att.10_-_Solicitation_Question_Response_Form-17.docx

RFP M67854-13-R-7803

DATE:

2/19/2013

CONTRACTOR QUESTION

SUBJECT:

Range Control Network Switch

SPECIFIC QUESTION:

3.3.1.9.3 Range Control Network Switch

For all communication equipment the contractor shall provide all patch cables necessary to complete the installation. All switches shall have a MTBF greater than 2MIL hours and a five year warranty.

It appears the number quoted for MTBF (“greater than 2MIL hours”) of 2 million hours (228 years) is a mistype. Will the Government update the document to reflect a more appropriate number?

REFERENCE: Attachment_1-_Statement_of_Work.pdf dated Jan 2013

GOVERNMENT RESPONSE

We are expecting the MTBF to be empirically-predicted for the sake of this contract. In this situation, MTBF can be confusing because when measured as an experimental value, it gives counter-intuitive results. An empirically-predicted MTBF of 228 years is unlikely to result in a usable life of 228 years, nor anything close. This is because the failure rate increases as the system approaches the end of its service life. When conducting MTBF predictions, on the other hand, we will be operating early enough during the service life, that λ will be comparatively small.

We are expecting the MTBF to be determined empirically, calculated as the inverse of the failure rate, λ.

Predicted MTBF=1/ λ= The MTBF of 2,000,000 hours equates to approximately 2% of systems burning out during the first five years.

This should be achievable with industrial quality switches.

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