Process analysis initially involved sampling the variety of process streams or webs and transporting samples to quality control or central analytical service laboratories. Time delays for analytical results due to sample transport and analytical preparation steps negated the value of many chemical analyses for purposes other than product release. Over time it was understood that real-time measurements provided timely information about a process, which was far more useful for high efficiency and quality. The development of real-time process analysis has provided information for process optimization during any manufacturing process. The journal Analytical Chemistry (journal) publishes a biennial review of the most recent developments in the field.
The first real-time measurements in a production environment were made with modified laboratory instrumentation; in recent times specialized process and handheld instrumentation has been developed for immediate analysis.