Rockwell Automation Discrete Machine Performance Solution - Manual (Page 29)

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4 • P
erformance Data
Collecting Performance Data
Chapter objectives
This chapter provides an description of some of the concepts and configuration necessary
to collect performance data using the Discrete MPS.
What is the OEE rating?
Discrete MPS uses an OEE (Overall Equipment Effectiveness) model to measure the
performance of manufacturing equipment. The OEE model yields a single performance
rating for every activity area (workcell, line, area, or plant) being monitored, thereby
providing a simple way to determine quickly if an activity area is performing adequately.
The OEE value can be used to assess a single machine’s performance over time or to
compare the performance of machines to each other.
Three components contribute to an OEE value: availability, throughput, and quality. Each
is a percentage, and the OEE value is the product of these three percentages, and therefore
is also a percentage.
Availability is the ratio of running time to available time. Available time may be defined
by a schedule or modified by planned downtime events such as preventive maintenance.
Available time may also be modified by events, such as being starved for parts or being
blocked by a downstream process.
Throughput is the performance of a machine when it is running compared to its ideal
cycle time. The ideal cycle time will depend upon the product being produced and is
measured in units of seconds per part.
Quality is the percentage of good parts that are produced.
The OEE calculation that is used by Discrete MPS is the product of these three
components:
The Discrete MPS Configuration Workbook Excel file provides a step-by-step process and tips
for determining the information necessary to configure the Discrete MPS.
Availability RunningTime AvailableTime ⁄ =
Throughput TotalParts IdealCycleTime × ( ) RunningTime ⁄
=
GoodParts TotalParts Scrap – =
Quality GoodParts TotalParts ⁄
=
Discrete.book Page 23 Wednesday, December 8, 2004 2:22 PM