System Sustainment

The following sections are included:

• Preface
• About the Authors
• Contents

“Sustainment” (as commonly defined by industry and government), is comprised of maintenance, support, and upgrade practices that maintain or improve the performance of a system and maximize the availability of goods and services while minimizing their cost and footprint or, more simply, the capacity of a system to endure. System sustainment is a multi-trillion-dollar enterprise, in government (infrastructure and defense) and industry (transportation, industrial controls, data centers, energy generation and others). Systems associated with human safety, the delivery of critical services, important humanitarian and military missions and global economic stability are often compromised by the failure to develop, resource, and implement effective long-term sustainment strategies. System sustainment is unfortunately, an area that has traditionally been dominated by transactional processes with less than optimal strategic planning, policy, or methodological support.

Organizations that operate critical systems use the system’s readiness or operational availability (A_o) as a key indicator of its success. These metrics are usually expressed as the percentage of total units available and capable of performing a mission at any given time. If a system is not ready when it is needed, its performance characteristics are of no use. There are two ways to achieve high readiness. One approach is to support the system with an extensive logistics system that can provide the required spare parts and other support when and where they are needed. An alternative approach is to design and develop systems that are highly reliable, thus minimizing the support required. The mechanism most generally used to manage the trade-offs between these two approaches is to calculate the system’s total ownership costs (TOC), i.e., the cost to develop, produce, operate, and maintain the system through its life cycle. The goal then is to design new systems to be more reliable (fewer failures) and more maintainable (fewer resources needed) without excessive increases in the cost of the system or spares. The result will be a system that meets the necessary system readiness, with a lower TOC…

A key to predicting and optimizing a system’s needed maintenance resources (Chapter 4) is an understanding of the demand for maintenance. The demand for maintenance is primarily driven by the reliability of a system. If one does not understand the reliability of their system, then they are relegated to always performing corrective maintenance, i.e., simply fixing the system after something breaks. The first step to understanding a system’s reliability is to understand how and why the system fails.

Maintenance is the practice of keeping systems operational. Maintenance takes place before or after a failure (or both). Maintenance involves functional checks, servicing, repairing or replacing of necessary devices, equipment, machinery, building infrastructure, and supporting utilities in industrial, business, governmental, and residential installations…

Availability is the ability of a service or a system to be functional when it is requested for use or operation. The concept of availability accounts for both the frequency of failure (reliability) and the ability to restore the service or system to operation after a failure (maintainability). The maintenance ramifications generally translate into how quickly the system can be repaired upon failure and are usually driven by logistics management. The concept of availability only applies to “repairable” or “restorable” systems that are either externally maintained or self-maintained…

Inventory is a stock or store of goods or services, kept for use or sale in the future. Inventory analysis exists at two different levels: (1) the inventory of finished goods or end-items that are available for sale or use; and (2) the inventory of parts and materials needed to support future manufacturing and/or the sustainment of systems. Inventory management represents the process of determining how much inventory you have, the state of that inventory, how and where to store the inventory, and under what conditions the inventory needs to be replenished and by how much…

Supply chains are commonly defined as the network between a company and its suppliers used to produce, distribute and sustain a specific product to a final customer. The supply chain can also represent the sequence of steps necessary to combine or transform a set of components into a system for the customer. This network includes many different activities, people, organizations, information, and resources…

In Section 1.4.4, of this book the concept or resilience was discussed. Resilience is the ability of a system to resist disturbances. The preceding chapters of this book have focused on the acquisition, hardware and software reliability, and various attributes of logistics associated with sustaining systems. In this chapter we look briefly at several other elements that are essential to creating and maintaining system resilience including: workforce aging, technology management, system end-of-support, and other topics.

In this chapter, we will be discussing contracts and how they are used when contracting for sustainment.

A contract is a mutually binding legal relationship obligating the seller to furnish the supplies or services and the buyer to pay for them. In the case of sustainment, the sellers are the sustainment providers; we will also refer to them as contractors or suppliers. The buyers are the system operators, and we will also refer to them as operators, owners, customers, or users…

As technological innovation continues to accelerate, system sustainment is not standing still as it adapts to the changing landscape. Potentially the defense, political, economic, and supply-chain stars are aligning to place a greater emphasis on system sustainment than ever before…

The following sections are included:

• Appendix A. Discounted Cash Flow (DCF) Analysis
• Appendix B. Monte Carlo Analysis
• Appendix C. Discrete-Event Simulation (DES)
• Appendix D. Summary of Notation and Acronyms

The following section is included:

• Index