Asia e University

Malaysia institute 0f logistics

Intermediate logistics officer course(Executive bachelor in logistics management)

Assignment no3

Enhancing supply support

Ltcdr hamed Alghafri

Royal Navy of Oman

Date:23 MAY 2011

Contents

Introduction.................................................................................................................................................3

Reliability.....................................................................................................................................................3

Reliability modeling.....................................................................................................................................3

Availability...................................................................................................................................................4

Maintainability............................................................................................................................................4

Factors Affecting RAM.................................................................................................................................4

Conclusion...................................................................................................................................................5

References...................................................................................................................................................5

Introduction

Logistics engineering as a discipline is also a very important aspect of systems engineering that includes reliability engineering. It is the science and process whereby reliability, maintainability, and availability are designed into products or systems. It includes the supply and physical distribution considerations above as well as more fundamental engineering considerations. For example, if we want to produce a system that is 95% reliable (or improve a system to achieve 95% reliability), a logistics engineer understands that total system reliability can be no greater than the least reliable subsystem or component. Therefore our logistics engineer must consider the reliability of all subcomponents or subsystems and modify system design accordingly. If a subsystem is only 50% reliable, one can concentrate on improving the reliability of that subsystem, design in multiple subsystems in parallel (5 in this case would achieve approximately 97% reliability of that subsystem), purchase and store spare subsystems for rapid change out, establish repair capability that would get a failed subsystem back in operation in the required amount of time, and/or choose any combination of those approaches to achieve the optimal cost vs. reliability solution. Then the engineer moves onto the next subsystem.

Reliability To enhance supply support every system requires a different level of reliability. A commercial airliner must operate under a wide range of conditions. The consequences of failure are grave, but there is a correspondingly higher budget. A pencil sharpener may be more reliable than an airliner, but has a much different set of operational

conditions, insignificant consequences of failure, and a much lower budget.Reliability is the probability of an item to perform a required function under stated conditions for a specified period of time. Reliability is further divided into mission reliability and logistics reliability..

Reliability modelingReliability modeling is the process of predicting or understanding the reliability of a component or system. Two separate fields of investigation are common: The physics of failure approach uses an understanding of the failure mechanisms involved, such as

crack propagation or chemical corrosion; The parts stress modeling approach is an empirical method for prediction based on counting the number and type of components of the system, and the stress they undergo during operation1.

Availability Availability is a measure of the degree to which an item is in an operable state and can be committed at the start of a mission when the mission is called for at an unknown (random) point in time. Availability as measured by the user is a function of how often failures occur and corrective maintenance is required, how often preventative maintenance is performed, how quickly indicated failures can be isolated and repaired, how quickly preventive maintenance tasks can be performed, and how long logistics support delays contribute to down time.

Maintainability Maintainability is the ability of an item to be retained in, or restored to, a specified condition when maintenance is performed by personnel having specified skill levels, using prescribed procedures and resources, at each prescribed level of maintenance and repair.

Factors Affecting RAM Many factors are important to RAM: system design; manufacturing quality; the environment in which the system is running and skills of the people operating and maintaining the system; the availability of materiel required to repair the system; and the diagnostic aids and tools (instrumentation) available to them2.

1 Logistic engineeringhttp://en.wikipedia.org/wiki/Logistic_engineering

2 DOD GUIDE FOR ACHIEVING.RELIABILITY, AVAILABILITY, AND MAINTAINABILITYReliability engineering. Page 1http://en.wikipedia.org/wiki/Reliability_engineering. 18 Jun 2011.

Conclusion

To enhance supply support during the concept exploration phase, ILS requires that reliability, maintainability, availability, and supportability (RMA&S) factors be considered in the design of the any system. This phase entails the solicitation and evaluation of alternative concepts designed to meet the requirements of the mission need. Preliminary Logistics Support Analyses (LSA's) provide the vehicle by which the systems and their components are evaluated.

References

Logistic engineeringhttp://en.wikipedia.org/wiki/Logistic_engineering

DOD GUIDE FOR ACHIEVING.RELIABILITY, AVAILABILITY, AND MAINTAINABILITYReliability engineering. Page 1http://en.wikipedia.org/wiki/Reliability_engineering. 18 Jun 2011.

Reliability theory

http://en.wikipedia.org/wiki/Reliability_theory

Integrated logistics support

http://en.wikipedia.org/wiki/Integrated_Logistics_Support

Availability

http://en.wikipedia.org/wiki/Availability