This article is a collaboration between the University of Tennessee Reliability and Maintainability Center , Convergence Training, and RedVector. Maintainability is the ease with which a product can be maintained in order to isolate defects or their cause, correct defects or their cause, meet new requirements, make future maintenance easier, or cope with a changing environment. The design emphasis on maintainability is to reduce the maintenance burden and Supply Chain by reducing the time, personnel, tools, test equipment, training, facilities, and cost to maintain the system. Maintainability and Reliability work together in developing design solutions for a system. One of the exit criteria of the Engineering, Manufacturing, and Development phase is demonstrating reliability, availability, maintainability, and sustainment features are included in the design of a system. Reactive maintenance and repeated corrective maintenance on a perpetually failing asset is no way to do business.

Figure 1-1 shows three examples of unit size quality profiles (print readers can view full-color figures for this and the other quality profiles that follow in our repository for this book). For consistency, we are using Java code snippets throughout the book. However, the guidelines described in this book are not specific to Java. In fact, SIG has benchmarked systems in over a hundred programming languages based on the guidelines and metrics in this book. SIG has collected empirical evidence that issue resolution and enhancements are twice as fast in systems with above-average maintainability than in systems with below-average maintainability. A factor of two is a significant quantity in the practice of enterprise systems.

h European Symposium on Computer Aided Process Engineering

Passengers of the airline system expect accurate delivery of information to the destination. Passengers expect flights to depart and arrive within reasonable time boundaries. When these boundaries are crossed, passengers are likely to use a different airline or not fly at all. Similarly, when an application is being used, the user expects a reasonable response time from the application, which is dependent on the timely delivery of information across the system.

Human Systems Integration to optimize total system performance and minimize life-cycle costs. This includes all HSI domains to design systems and incorporate technologies that require minimal manpower, provide effective training, can be operated and maintained by users, are suitable , and survivable . Minimum Levels of Service – defined under the definition of availability – that have to be maintained under all conditions.

The Aircraft Design Process

Simplify the execution of maintenance work and indirectly improve the maintainability of their facility. The base which houses the driving motor is designed to separate from the jars which are easily removable and replaceable if blades get damaged . Instead of using multiple different types of parts and components, it is recommended to minimize variety among parts in order to minimize inventory, tooling, and training requirements. An easy way to define maintainability is through an event of a flat automobile tire.

It is no coincidence that spare tires can be fitted at all tire locations and that automobile manufacturers provide bolts on each tire that can be tightened and loosened with the same wrench size. The star ratings serve as a predictor for actual system maintainability. SIG has collected empirical evidence that issue resolution and enhancements are twice as fast in systems with 4 stars than in systems with 2 stars. Even though ISO does not describe how to measure software quality, that does not mean you cannot measure it.

Maintainability vs. Reliability

Reliability is making assets “last” and work for as long as possible. Combining high maintainability with high reliability is what ensures high asset availability – that is, a good percentage of uptime. That’s why reliability-centered-maintenanceaims to keep assets functional and available for as long as possible. Maintainability is improved in the sense that there will be less need to disengage the equipment from the production line to visually inspect specific parts. Similarly, availability will be improved as unnecessary downtime will be curtailed and will occur only when the equipment is nearing its potential failure point in the P-F interval. Throughout the lifecycle of the asset by maintenance and service reliability engineers that have key data points on asset health and performance.

You can tell that Jenkins complies to the unit size guideline for 4 stars , since the percentages of code in each category are lower than the 4-star cutoffs. SIG divides the systems in the benchmark by star rating, ranging from 1 star to 5 stars . The distribution of these star ratings among systems from 1 to 5 stars is 5%-30%-30%-30%-5%. Thus, in the benchmark the systems that are among the top 5% are rated 5 stars. In these systems, there are still violations to the guidelines, but much fewer than in systems rated below.

maintenance

These systems had such a low degree of modification efficiency and effectiveness that the system owner could not afford to maintain it. To keep the metrics simple but also practical, we determine the quality of a complete codebase not by the code’s number of violations but by its quality profiles. A quality profile divides metrics into distinct categories, ranging from fully compliant code to severe violations. By using quality profiles, we can distinguish moderate violations from severe violations . After the next section, which discusses common misunderstandings about maintainability, we explain how quality profiles are used to measure the maintainability of a system.

MaintainX is a mobile app for maintenance workers that simplifies day-to-day work order tasks. Our software eliminates the paperwork, so you can spend more time on crucial work, reduce downtime, and increase efficiency. Likewise, when data indicates that a piece of equipment is no longer maintainable, an equipment upgrade may be necessary. Setting maintenance benchmarks and capital expenditure allocations to increase equipment uptime may be cost-effective. Reliability refers to how likely an asset performs as expected, without failure, under normal operating conditions. Conversely, an unreliable asset experiences frequent unexpected failures.

The concept of RAM: Reliability, Availability, and Maintainability

To clarify further, home maintenance and housekeeping included preparing meals, laundry, cleaning, childcare, gardening, pet care, home repairs, and paperwork. We have a large team of IT staff who provide ongoing https://www.globalcloudteam.com/ system and applications maintenance. This equation is explicit for availability, so relatively easy to calculate, and thus popularly used. However, it is correct only when the system can be repaired only once.

• The focus is to get the equipment up and running as quickly as possible, with the lowest possible cost incurred on maintenance.
• We understand that it is hard to see whether an individual “violation” of the guidelines in this book influences the overall maintainability of the system.
• Initial maintenance plans identify system level servicing requirements, on-equipment repairs, and planned maintenance levels.
• Reliability is making assets “last” and work for as long as possible.
• Reliable plants are safer plants as well–when reliability metrics go up, safety incident metrics tend to go down.

It may be necessary to develop allocations for both corrective and scheduled maintenance actions as noted above. We know now that maintainability is a quality characteristic on a scale. Clearly, a complex system is easier to maintain by an expert than by a less experienced developer. By benchmarking, at SIG we let the metrics in the software industry answer this question.

Browse Definitions.net

In this section, we discuss some misunderstandings about maintainability that are encountered in practice. Remember that you are writing code not just for yourself, but also for less-experienced developers what is maintainability that come after you. More often than not, such systems are written off before they ever see a 1.0 release. Ways are identified to increase quality or prevent future bugs from occurring .