Manual assembly is generally better suited to lower-volume, changeable or judgement-heavy processes. Automated assembly systems are usually a stronger fit when the process is stable and production volumes, takt time, quality requirements and labour savings justify the investment.

Leak testing measures how much gas or fluid escapes from a component under defined conditions, while pressure testing checks whether the component can withstand a specified pressure without failure. They answer different questions, which is why passing a pressure test does not automatically mean a part will pass a leak test.