Integrated logistics support (ILS) is an integrated approach to the management of logistic disciplines. Although originally developed for military purposes, it has been applied by the private sector as well.
In general, ILS plans and directs the identification and development of logistics support and system requirements, with the goal of creating systems that last longer and require less support, thereby reducing costs and increasing return on investments. ILS therefore, addresses these aspects of supportability not only during acquisition, but also throughout the operational life cycle of the system. The impact of ILS is often measured in terms of metrics such as reliability, availability, maintainability and testability (RAMT), and sometimes System Safety (RAMS).
All elements of ILS are ideally developed in coordination with the system engineering effort and with each other. Tradeoffs may be required between elements in order to acquire a system that is:
Logistics Support Analysis (LSA)
The planning for ILS for a system may be contained in an Integrated Logistics Support Plan (ILSP). ILS planning activities coincide with development of the system acquisition strategy, and the program will be tailored accordingly.
The Logistics Support Analysis (LSA) process is tailored in accordance with the maturity of the system/equipment design. The LSA provides a foundation for the ILS program by generating source data and maintenance plans, which will direct other ILS elements such as training, technical publications and provisioning. The source material will be identified during the development of a maintenance philosophy through the implementation of the LSA itself. The maintenance philosophy should adopt and concur with the program maintenance concept and ensure that supportability requirements are considered and incorporated into the design of an equipment/system.
Typical Logistic Support Analysis (LSA) tasks that are performed are as follows:
Life Cycle Cost Analysis (LCC);
Level of Repair Analysis (LORA);
Maintenance Task Analysis (MTA);
Meantime to Repair Analysis (MTTR);
Reliability, Maintainability and Availability (RAM);
Spares (Optimisation) Modelling and Analysis (SM);
Failure Modes, Effects & Criticality Analysis (FMECA).
Life Cycle Costs Analysis (LCC):
The Life Cycle Costs (LCC) analysis determines the cost to acquire and own a system over its useful lifetime. That cost, often referred to commercially as Total Cost of Ownership (TCO), is the estimated total of direct, indirect, recurring, non-recurring, and other related costs that are expected to be incurred. The LCC includes costs associated with design, research & development, investment, operations, maintenance, support and disposal of a system over its life cycle.
Subsequent LCC Analysis (LCCA) allows for the conduct of various costing options that provide the owner with the effects of various alternate decision paths.
Level Of Repair Analysis (LORA):
Level of Repair Analysis (LORA) is an analytical methodology used to determine where an item will be replaced, repaired, or discarded based on cost considerations and operational readiness requirements. For a complex engineering system containing thousands of assemblies, sub-assemblies, components, organized into several levels of indenture and with a number of possible repair decisions, LORA seeks to determine an optimal provision of repair and maintenance facilities to minimize overall life-cycle costs. Logistics personnel examine not only the cost of the part to be replaced or repaired but all of the elements required to make sure the job is done correctly and cost effectively.
This analysis can be implemented as a standalone analysis, but is generally integrated in the Logistics Support Analysis activity on an iterative basis to determine an optimal provision of repair and maintenance facilities to minimize overall life-cycle costs.
Maintenance Task Analysis (MTA):
A completed Maintenance Task Analysis (MTA) will detail the resources required to implement effective corrective and preventative maintenance tasks for a system and/ or equipment. It identifies the steps, spares and materials, tools, support equipment, personnel skill levels as well as any facility issues that must be considered for a given corrective and preventative maintenance task. Also included in the MTA is data such as task intervals and elapsed times required for the performance of each task.
Meantime to Repair Analysis (MTTR):
A Maintainability Mean Time to Repair (MTTR) prediction analysis provides calculated information regarding various aspects of maintenance. The goal of performing a Maintainability Analysis is to determine the amount of time required to perform repairs and maintenance tasks. In other words, if a system does fail, how long will it take to fix it? The MTTR analyzes all of the removable items in a system for corrective maintenance action. More importantly, MTTR can then be used in a reliability prediction in order to calculate "availability". Availability is the probability that an item is an operable state at any time, and is based on a combination of failure rate and MTTR. Maintainability is integrated with Reliability Prediction.
Reliability, Availability and Maintainability (RAM):
The discipline is also called Dependability and Safety. It is an engineering discipline, with interfaces to all technical disciplines (system, electrical, mechanical, thermal, software, human factors, operations, etc.) and to Product Assurance. For cost efficiency reasons, RAM engineering should be performed early in the project phase (starting from the mission definition phase). RAM analyses are performed in close cooperation with the design and operations specialists responsible for implementing the results of the analysis.
Spares (Optimisation) Modeling (SM):
The Spares Modelling along with the LSA effort and LORA will determine where and how items are repaired. The spares modelling analysis would basically determine the recommended quantity of spare parts required to satisfy the customer's requirements, and the optimum location of each type of spare part; this is commonly referred to as the range of spares. An assumption generally made when assessing a system's availability is that the required resources to implement a maintenance task will be readily available, or on-hand, including the necessary spare parts.
Failure Modes, Effects and Criticality Analysis (FMECA):
A FMECA is a bottom up approach to analysing system design and performance. This analysis can be the individual components (referred to as a piece part FMECA) or the lowest level assemblies in the system (referred to as a functional FMECA). A successful FMECA activity helps to identify potential failure modes based on past experience with similar products or processes and the criticality of those potential failure modes, enabling those failures to be designed out of the system with the minimum of effort and resource expenditure, thereby reducing development time and costs. Failure modes are any errors or defects in a process, design, or item, especially those that affect the customer, and can be potential or actual. Effects analysis refers to studying the consequences of those failures.