1. OEE ( Overall Equipment Effectiveness) manoji@yahoo.com
OEE : [Availability % ] X [Performance %] X [ Quality %]
a b c
Down Time Loss
A) How to calculate OEE ? Speed Loss
Quality Loss
a) Machine Availability
TYPES OF LOSSES ( Part of Six big Losses) - Read below for six big losses
Breakdowns : 1. Tooling Failures
2. Unplanned Maintenance
3. General Breakdowns
4. Equipment Failures
Setup & Adjustments: 1. Setup / Changeover This should address under
2.Materail Shortage setup time reduction
3.Operator Shortage programs
4.Major Adjustments
5.Warm-Up Time
b) Machine Performance%
Let's assume machine makes 1000 PCS during 5.00Hours of Work
Please note that we consider the production only during up-time
Machine Standard rate ( PCS) : 300PCS/HOUR
Current Performance ( PCS) : 1000PCS/5 HOURS
200PCS/HOUR
Machine Performance % : (200/300)X100 %
66.7%
2. TYPES OF LOSSES ( Part of Six big Losses)
Small Stops 1. Obstructed Product Flow
2. Components Jams
3. Misdeeds This includes stops that are
4. Sensor Blocks under five minutes and not
5. Delivery Blocked require maintence
6. Cleaning / Checking personal for recitification
Reduced Speed or 1. Rough Running
Slow Cycles 2.Below nameplate capacity
3.Under design capacity
4.Equipment Wear
5.Operator Inefficiency
c) Quality %
Let's assume machine makes 1000 PCS during 5.00Hours of Work
and 200 PCS are rejected by QAD.
Total Produced during 5.00 Hours ( PCS) : 1000
Quality Rejected ( PCS) : 200
Quality % : accepted products /total products
80.0%
TYPES OF LOSSES ( Part of Six big Losses)
Porduction Rejects 1. Scrap
2. Rework
3. In-process damage Rejctions during Steady
4. In-process expiration state production
5. Incorrect assembly
Startup Rejects 1. Scrap Rejects during worm-up
2.Rework start-up, other early
3. In-process damage production , may be improper
4. In-process expiration set-up…..etc
5. Incorrect assembly
OEE : [Availability % ] X [Perfomance %] X [ Quality %]
0.794X0.667X0.800
42.4%
3. B) Six Big Losses
http://www.oee.com/images/pt-oee-six-big-losses.png
C) How to Address SIX Big Losses ?
Breakdowns : Eliminating unplanned down-time is important in improving OEE.
You can use Pareto Charts to prioratize the severe losees and Root Cause Analysis for
solutions.
Setup and Adjustments:
This is measured between last good part produced before setup to first good part
produced after setup. Tracking setup time is important to reduce this loss togather with
an active program to reduce this time such as SMED ( Single Minute Exchange of Dies)
( Eg : Use of prefabricated setups , Magnetic clamps on Injection modling MC)
Small Stops ad Reduced Speeds :
This is very difficut to record and monitor . Comparing completed cycle times and
ideal cycle time , errant cycles can be spotted. Then , RCA ,PDCA , DMAIC , 8D
problem solving can be used.
Startup Rejects and Production Rejects: Startup Rejects and Production Rejects are two different things
root causes are also different between startup and steady-state production. Parts require
any kind of reworks are rejects . Often a six sigma program can be used to bring the
quality to near perfect level.
D) How to calculate OEE in plant ?
Let's say a plant can have few machines,
OEE: [Available Time MC1+Available Time MC2….]/[Scheduled Time MC1+Scheduled Time MC1…..]
X[Current Performance MC1+MC2…]/[Rated Performance MC1+MC2..]X[Approved Quantity MC1+
MC2…]/[Total Quantity MC1+MC2..]
E) How to calculate OEE in a Group of Plants?
Let's say a group of companes has three plant assets,
OEE : [OEE1+OEE2+OEE3]/3
F) What is world class OEE Levels ?
Availability 90%
Performance 95%
Quality 99.9%
OEE 85%
4. G) Visual OEE
Plant floor real time display of live OEE data for maximum team involvement.
http://www.vorne.com/
Reference
http://www.smartandon.com/files/OEE.jpg
http://www.oee.com/images/pt-oee-six-big-losses.png
http://www.vorne.com/