Plant uptime and production uptime
Plant Uptime is a process or production performance measure or KPI
which is used extensively in many industries as an alternative or together with plant downtime
. It is sometimes preferred to plant downtime because it incorporates all the possible downtime causes both scheduled and unscheduled therefore representing the time that the plant is actually up and running producing value added goods
for customers. In the end this is the time the production line or process is making money for the business. Plant Uptime or plant availability is also a component in calculating plant and process OEE
Plant uptime is calculated as a percentage figure of plant run time divided over available production time:
Plant Uptime = plant run time (production) / Total available time to run or produce
Plant run time = Total available time to run - scheduled and unscheduled downtime/stoppages.
It is important to track plant or process uptime in order to identify any increase in plant stoppages, product changeover times
deterioration of plant reliability and maintenance issues such as plant breakdowns.
. In order to find the reasons for the decrease in plant uptime the stoppage causes must be noted including the time of stoppage, machinery affected, length of stoppage, any maintenance performed on the plant
and root cause. This will provide a firm basis for rectifying issues affecting plant uptime and a manner of tracking the results of any lean manufacturing initiatives.
Although downtime is a good kpi to track it can become very complicated when it is spilt down into the different downtime classifications and the true downtime figure for a plant or process may become subjective, this is where it is preferable to use plant uptime in order to gauge management's ability to operate the plant or process as efficiently as possible with minimal stoppages for whatever reason.
More lean concepts and terms