Time : Preferably in minutes
1 unit = Production in single cycle(theoretical cycle time).
example 1: Production in single cycle = 10 MT
Total Production/shift = 100 MT
units produced = 100/10 = 10
example 2: Production capacity/cycle = 224 pieces
Total Production/shift = 2240 pieces
Units produced = 2240/224 = 10
example 3: Production capacity/shift = 500 square metre(here theoretical cycle time is shift time i.e.480 mins)
Total Production/shift = 250 square metre
Units produced = 250/500 = 0.5
Overall Equipment Effectiveness:
OEE breaks the performance of a manufacturing unit into three separate but measurable components: Availability, Performance, and Quality. Each component points to an aspect of the process that can be targeted for improvement. OEE may be applied to any individual Work Center, or rolled up to Department or Plant levels. This tool also allows for drilling down for very specific analysis, such as a particular Part Number, Shift, or any of several other parameters. It is unlikely that any manufacturing process can run at 100% OEE. Many manufacturers benchmark their industry to set a challenging target; 85% is not uncommon.
OEE = Availability Rate x Performance Rate x Quality Rate
The Availability portion of the OEE Metric represents the percentage of scheduled time that the operation is available to operate. The Availability Metric is a pure measurement of Uptime that is designed to exclude the effects of Quality, Performance, and Scheduled time loss.
Availability Rate = (shift hours - (personal allowance+cleaning time+management loss))/(scheduled hours - (breakdown time + job change loss + tool change loss + start-up loss))
Period(e.g.shift hours ) : 480 minutes.Other type of periods also can be entered but other parameters to be changed accordingly.
Personal allowance:Lunch time , Tea break , natural calls,etc.
management loss: Priority fixing Time, material flow time , etc.
scheduled hours = (shift hours - (personal allowance+cleaning time+management loss))
The Performance portion of the OEE Metric represents the speed at which the Work Center runs as a percentage of its designed speed. The Performance Metric is a pure measurement of speed that is designed to exclude the effects of Quality and Availability.
Performance Rate = (theoretical cycle time x Units produced)/(scheduled hours - (breakdown time + job change loss + tool change loss + start-up loss))
The Quality portion of the OEE Metric represents the Good Units produced as a percentage of the Total Units Started. The Quality Metric is a pure measurement of Process Yield that is designed to exclude the effects of Availability and Performance.
Quality Rate = good units/units started
good units produced <= Units produced <= units started.
good unit : fit for use