Which of the following is an approximate of the average or mean time until a component’s first failure or disruption in the operation of the product, process, procedure, or design takes place?

A.
MTBF

B.
HMA

C.
MSDS

D.
MTF

Explanation:
Mean TimetoFailure (MTTF) is an approximate of the average, or mean time until a components first failure, or disruption in the operation of the product, process, procedure, or design takes place. MTTF presumes that the product CANNOT be repaired and the product CANNOT continue any of its regular operations.

In many designs and components, MTTF is especially near to the MTBF, which is a bit longer than MTTF. This is due to the fact that MTBF adds the repair time of the designs or components. MTBF is the average time between failures to include the average repair time, or MTTR. Answer option A is incorrect. Mean time between failures (MTBF) is the predicted elapsed time between inherent failures of a system during operation.

Answer option B is incorrect. Hash-based Message Authentication Code (HMAC) is a specific construction for calculating a Message Authentication Code (MAC) involving a cryptographic hash function in combination with a secret key. As with any MAC, it may be used to simultaneously verify both the data integrity and the authenticity of a message. Any iterative cryptographic hash function, such as MD5 or SHA-1, may be used in the calculation of an HMAC. The resulting MAC algorithm is termed HMAC-MD5 or HMAC-SHA1 accordingly. The cryptographic strength of the HMAC depends upon the cryptographic strength of the underlying hash function, the size of its hash output length in bits, and on the size and quality of the cryptographic key.

Answer option C is incorrect. A Material Safety Data Sheet (MSDS) is a document that specifies a set of guidelines regarding the proper handling, transporting, storage, and disposal of a hazardous substance or chemical. It also contains information on first-aid treatment, as it is helpful in case of accident or exposure to toxic material. This sheet is displayed in areas where such untoward incidents can be possible, so that in case of any emergency, proper actions, based on the information provided on the sheet, can be taken to handle the situation. The companies or organizations are required to create and paste MSDS in hazardous areas.