If you are familiar with the OSI seven layer model for network communications, then the concepts behind the TMN model should be easy to recognise. Basically, take a complex and extensive problem,split it into smaller, more manageable pieces and formally define the interfaces of each piece. There are four layers to the model, that map the management functions and communication for the operation, administration and maintenance (OA&M) of networks and services in a multi-vendor environment.

When Network Management is discussed, then this is usually taken to imply the functionality defined by Layers 1 & 2 of the model, together with a well defined northbound interface into Layer 3. For example, the management of the corporate backbone and the billing of various departments for bandwidth to the mainframe, where the link to the billing system would be the northbound interface to Layer3.

http://www.casewise.com/downloads/installs/dldetail.php?&install=140

6- eTOM Model v.3.0

The enhanced Telecom Operations Map (eTOM) Business Process Framework serves as the blueprint for process direction and the starting point for development and integration of Business and Operations Support Systems (BSS and OSS respectively).

The eTOM Framework also helps drive TM Forum member’s work to develop NGOSS solutions. For service providers, it provides a neutral reference point as they consider internal process reengineering needs, partnerships, alliances, and general working agreements with other providers.

For suppliers, the eTOM Framework outlines potential boundaries of software components, and the required functions, inputs, and outputs that must be supported by products.
 

http://www.vibrationandshock.com/news/news6/nl6.htm

8- FIVE NINE Reliability
by Larry Shull

During the heyday (1960-1973) of the Saturn/Apollo Program there was a term used and understood by all involved, FIVE NINE RELIABILITY. Interpretation: each and every part on any component of the entire Saturn assembly was proven to be 99.999% reliable under full scale loading conditions. This, in effect, means that 99,999 times out of 100,000 tests each part had functioned as designed. Of course, every part was not tested that many times, but its performance was proven to meet these standards. This proven reliability was the major reason for the superb performance of the entire Apollo program. Quality control was about hardware, not about paper work as it is today.

Five nine reliability is a thing of the past, based on material and equipment available on today's markets. Automobiles must be worked on before they can be driven off the show room floor; new toasters, out of the box, fail to perform when plugged in for the first time; buy five shirts off the rack, when opened at home four have defects, some serious enough to return the shirt. This holds true for almost anything on the market, mechanical, electronic, material, and so on. We have generations of younger people who accept this as the "norm", never having experienced anything better. Poor performance is expected from almost any endeavor. This attitude is carried to the test beds of mechanical items. Failure of sensors used to determine performance is shrugged off as "nothing unusual!" If a strain gage, or other type transducer fails to provide the expected answer the sensor is assumed "bad".

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