How can you figure out how effective your equipment is all around? (OEE)

OEE is widely getting used in manufacturing and repair industries for calculator ad human efficiency. this is often a metric quantity and may be calculated easily. OEE has become an integral a part of lean manufacturing principles. so as to initiate any productivity improvement in any organization, it's recommended that OEE should be calculated to form it as a baseline for improvement efforts.

To calculate performance of organization in terms of OEE, we've to divide it into three measurable terms, quality, availability and performance. Each parameter from any manufacturing organization are often selected for improvement efforts. Also one advantage of it's that, it are often applied to whole plant, any single department or any workstation. during this effort 100% OEE is taken as ideal case and can't be achieved, however 85% is targeted by many organization.

The formula for calculation of OEE is

OEE = Availability x Performance x Quality

To calculate actual value of OEE, we take example of a producing plant, where machine availability for manufacturing is 87% and performance level of that specific plant is 94% and therefore the component being produced are of 90% good quality. So, the OEE of that plant is

OEE = 87 x 94 x 90 = 73.6 %

Now we glance , the way to calculate above mentioned three parameters for calculation of our desired values.

To calculate plant availability, we've to first look, what proportion time a plant is operational and prepared for manufacturing activities. From this point , we subtract planned maintenance and down time (Machine failure, lunch break, tea breaks and idle time). Ultimately we get full operation time. From this point , we again subtract other un-necessary time delays to urge net time availability for production. this point delay are often thanks to unscheduled breakdown, electricity problem, tool and work piece change over time, non-availability of staple and non-availability of proper tools.

Performance is that the efficiency of machine and operator. Machine efficiency might not be up to rated values thanks to many causes like, wear & tear, misfeed and non-availability of proper tool. And operator efficiency are often less thanks to less skilled person. If we multiply both efficiencies, then we get performance of operator and machine.

Quality is measured by calculating total number of products produced and form them subtracting rejected and re-work pieces.

To calculate actual value of OEE, we take example of plant, which work on 8 hour sift basis. Rests of values are as follows:

Total time = 8 hour/480 minutes Production breaks = 1.5 hour/90 minutes Machine down time = 20 minutes Ideal production rate of machine = 55 pieces Total production = 17665 Total rejected = 430

Total planned production time = total time - production breaks =480 - 90 = 390 minutes

Total operating time = 390-20 = 370 minutes

Total good pieces produced = 17665 - 430 = 17235 pieces

Machine availability = Total operating time / Total planned production time = 370/390 = 0.9487 = 94.87 %

Performance = (Total production / Total operating time) / Ideal production rate of machine = (17665/370)/55 = 0.8680 = 86.8 %

Quality = Total good pieces produced / Total production = 17235 / 17665 = 0.9756 % = 97.56%

OEE = Machine availability x Performance x Quality

= 94.87 x 86.8 x 97.56

= 80.33 %

Hence the machine overall equipment effectiveness is 80.33%.

Performance Performance