The first step in designing a system comprises selecting the components such as Single Board Computer, power supply, LCD display etc to provide the best fit for your application. Processing power, unit costs, onboard I/O features such as number of USB, LAN or serial ports etc are taken into account. Other features such as physical size, power supply requirements, operational temperature range, LCD visibility in bright light, shock and vibration etc are also considered. Often components from more than one supplier are selected and interoperability is checked. Finally, any other no standard requirement such as software or hardware development etc is listed.