Читать книгу System Reliability Theory - Marvin Rausand - Страница 56

System reliability has been around since the 1940s. The relevance of reliability has increased steadily and we clearly see trends and challenges that will increase the relevance in the years to come. In this section, we briefly mention some of these trends and challenges. An overall trend is that customers expect new items to be BETTER, FASTER, and CHEAPER than the items they replace. More specific challenges include

1 Items get more and more complicated with a lot of embedded software. Hardware functions are replaced with software‐based functions. Because the software‐based functions are relatively cheap, many items are loaded with “nice‐to‐have” function that may also fail.

2 Most producers meet fierce international competition. To survive, this requires reduced development costs, shorter time to market, and less time spent on analyses and testing. New items have to be sufficiently reliable in the first concept version.

3 Customers require more and more of the items they purchase, related to functions, quality, and reliability. The requirements are often changing rapidly. Factors influencing item requirements are shown in Figure 1.9.

4 There is an increasing focus on safety and environmental friendliness and an increasing risk of item call‐back if the items should have safety‐related defects.

5 New items are increasingly made up of elements from a variety of subcontractors from many different countries, making it difficult for the main producer to verify the item reliability.

6 For some items, high‐speed operation reduces the tolerance of deviations and increases the consequences of failures, should they happen.

7 There is an increasing focus on warranty. Companies have disappeared because of excessive warranty costs.

8 An increasing number of items are now connected to a cybernetwork and are vulnerable to cyberattacks. Current challenges are related to the rapid developments of smart homes, smart cities, smart transport systems, the Internet of Things (IoT), cyber‐physical systems, systems of systems, and Industry 4.0. Within few years, we expect to see many more new initiatives of similar nature. This will make reliability analyses even more challenging.

Figure 1.9 Factors that influence item requirements.