Aridity as a factor in estimating the lifespan of electronic systems

Abstract

Environmental factors have been widely attributed as being among the core factors influencing electronic systems reliability (ESR) of electronic components, systems or devices. Most of the available interpretations of this influence are somewhat limited to descriptions of the environment being ‘Ground’, ‘Airborne’, ‘Naval’, ‘Commercial’ and so on, which only describe the ‘condition’ of the environment that the electronic system is used in. Aridity is a physical attribute used to characterise the extent of dryness or availability of water in an area, using which environmental conditions peculiar to any location can be deduced. For example, it is well-known that areas surrounding the equator are the most arid. These areas are characterised by high temperatures, low humidity, medium to large amounts of dust, solar and atmospheric pressure, etc. Consequently, we contend that by modelling the ESR assessment (in terms of failure rate), a property we loosely refer to as lifespan of an electronic system, in terms of aridity we can extend the interpretation of environmental impacts on ESR from descriptions of the environmental ‘condition’ to more ‘physical’ (or geographic) descriptions. To validate our proposal, we employed two simple yet veridical approaches. In the first approach, we compared the failure rate of a widely used electronic biometric (Electrocardiogram) ECG device based on standard environmental ‘conditions’ and reference values as available in many of the acceptable ESR software and tools (notably those in ReliaSoft, Isograph, etc.) assuming its deployment for use in two contrasting climatic conditions (such as those found in the desert Kingdom of Saudi Arabia (KSA) and the slightly milder climates obtainable in parts of China (specifically, the climate in Beijing). Notwithstanding the contrasting climatic conditions, based on this approach, fallaciously, the B 10 rating, a measure used to assess at which point the reliability of an ESR falls below 90%, were found to be close to 5 years when the failure rate for the device is predicted using conditions prevalent in the two countries. In the second approach, in order to model the role of aridity as an additional mechanism to estimate the environmental contributions to ESR, the lifespan of the same (ECG) device was evaluated based on the configuration proposed in this study using the average climatic conditions prevalent in five countries that are geographically spread across the length of the world. Our proposed approach estimates lifespans of 13, 39, 40, 42 and 45 years when the same device is deployed for use under average climatic conditions prevalent in the KSA, China, Japan, the USA and Britain respectively. Since aridity was used to reveal these interesting results, and it is known to vary with physical geographic location around the world, we conclude that, to some extent, the lifespan of electronic equipment is also influenced by the geographic location that it is deployed for use.