Overall Plant Effectiveness (OPE) is the ratio in percentage of
Actual Accepted Quantity Produced (Q2) to the Quantity that should have been produced in Total Scheduled Hours (T2xN)
That is, OPE = {Q2/T2xN}x100%
And, similarly,
Overall Equipment Effectiveness (OEE)
Is the ratio in percentage of
Actual accepted quantity produced (Q2) to the Quantity that should have been produced in Total Loading Hours (T3xN)
That is, OEE = {Q2/T3xN} x100%
(Where N is the 100% Rated Output per Hour)
Overall Equipment Effectiveness (OEE)
Can also be expressed as
OEE = Availability x Performance Rate x Quality Rate
Where,
Availability is the ratio in percentage of
Total Operating Hours (T4) to Total Loading Hours (T3)
Performance Rate is the ratio in percentage of Actual Quantity Produced (Q1) to Quantity that should have been produce in Total Operating Hours (T4)
Quality Rate is the ratio in percentage of
Actual Accepted Quantity Produced (Q2) to Actual Quantity Produced (Q1)
Wednesday, September 10, 2008
Friday, July 4, 2008
16 - YEILD LOSS
These are volume losses stemming from weight differences between raw materials and products or between all raw material input and the products.
The former are material losses caused by increasing wall thickness to more than the necessary level, in order to prevent casting defects (sand inclusion, surface flaws) in the raw materials or to cover the insufficient precision of shaping moulds. These losses sometimes cause the extension of machining time or the reduction of the service life of cutting blades.
The latter represents the difference between slag weight/gate weight/burr volume and product weight-material losses causing yield decline due to increased burr occurrence resulting from insufficient mould precision. In aluminium casting, the weight of runner and burr is applicable instead of the above weights.
This affects cost & not affecting the equipment OEE / OPE
The former are material losses caused by increasing wall thickness to more than the necessary level, in order to prevent casting defects (sand inclusion, surface flaws) in the raw materials or to cover the insufficient precision of shaping moulds. These losses sometimes cause the extension of machining time or the reduction of the service life of cutting blades.
The latter represents the difference between slag weight/gate weight/burr volume and product weight-material losses causing yield decline due to increased burr occurrence resulting from insufficient mould precision. In aluminium casting, the weight of runner and burr is applicable instead of the above weights.
This affects cost & not affecting the equipment OEE / OPE
15- DIE,JIG & TOOL LOSS
Die, jig, and fixture losses represent expenses arising as a result of manufacturing of new moulds, replacement due to the end of service life or breakdown, repair following wear, manufacturing or repair of mould parts, and manufacturing or repair of jigs and tools. If the repair frequency is high, expenses naturally grow
This affects cost & not affecting the equipment OEE / OPE
(14) Energy Loss
These are losses of such energy as electric power, fuel, steam, air, and water (including wastewater).
Improvement has been achieved with regard to major energy losses, but a considerable number of minor losses are left un-rectified, so there is much room for improvement. In the case of hydraulic equipment, various problems must be detected by studying the following points:
- Is the pressure-setting appropriate?
- Is the holding time appropriate?
- Is the hydraulic pump type suitable (variable capacity type)?
- Is the hydraulic circuit suitable?
Detected problems should be solved one by one. Finding and improving many minor energy losses adds up to great results.
This affects cost & not affecting the equipment OEE / OPE
Improvement has been achieved with regard to major energy losses, but a considerable number of minor losses are left un-rectified, so there is much room for improvement. In the case of hydraulic equipment, various problems must be detected by studying the following points:
- Is the pressure-setting appropriate?
- Is the holding time appropriate?
- Is the hydraulic pump type suitable (variable capacity type)?
- Is the hydraulic circuit suitable?
Detected problems should be solved one by one. Finding and improving many minor energy losses adds up to great results.
This affects cost & not affecting the equipment OEE / OPE
(13)Measuring and adjustment losses
These are worker-hour losses that result from frequent implementation of measuring and adjustment to prevent occurrence of quality defects and flow-out.
This affects Availability, OEE & OPE.
This affects Availability, OEE & OPE.
(12)Logistics loss & failure to automate
These are personnel losses resulting from non-replacement with automated systems, although such replacement could be done. They include, for instance, cases in which automated loading and unloading leading to manpower reduction is not implemented, although it could be done. Also in this category are distribution losses, which occur because automation of distribution operations such as supply, shipment, and transport of parts and products is not enforced although it is possible.
This affects Availability & OPE
This affects Availability & OPE
(11)Line organisation losses
• These are waiting time losses involving multi-process and multi-stand operators and line-balance losses in conveyor work.
• This affects Availability, OEE & OPE
• This affects Availability, OEE & OPE
(10)Motion losses
• These include motion losses due to violation of motion economy, losses that occur as a result of skill differences, and walking losses attributable to an inefficient layout.
• This affects Availability, OEE & OPE
9. MANAGEMENT LOSSES
These are waiting time losses that occur during management, such as waiting for materials, instructions, power and defect repair
This loss is sub classified as follows.
• Want of tools
• Want of instructions
• Want of raw material
• Want of manpower
• Want of spare parts
• Want of container
This loss will affect only OPE & Availability.
This loss is sub classified as follows.
• Want of tools
• Want of instructions
• Want of raw material
• Want of manpower
• Want of spare parts
• Want of container
This loss will affect only OPE & Availability.
8. SCHEDULED DOWNTIME LOSS
These are time losses occurred when equipment is stopped for planned maintenance, as well as volume losses that occur due to equipment start-up. These are an unavoidable aspect of the equipment, so they occur based on the quality, safety, and reliability maintenance requirements of the equipment, although there are some differences in time requirements
The following problems are generally noted with respect to shutdowns:
• Past work patterns are followed without improvement.
Partially unnecessary work is carried out
. Parts are replaced before their service life has ended
. Work methods and standards are not sufficiently established.
• The critical path (work to regulate overall time) is unclear.
• There is no logical base for cycle-setting.
• Improvement work for cycle extension is insufficient.
• Study of time reduction is not implemented
Solving these problems, one by one, will lead to the reduction of shutdown time and cycle-time extension.
• This is equipment –related loss, wherein the equipment is “scheduled” to be kept under downtime due to certain permitted reasons.
• This loss is sub classified as follows.
• JH activity time
• PM activity time
• Meetings
• Development time
• Not scheduled at all
Mostly this loss will affect only OPE.
The following problems are generally noted with respect to shutdowns:
• Past work patterns are followed without improvement.
Partially unnecessary work is carried out
. Parts are replaced before their service life has ended
. Work methods and standards are not sufficiently established.
• The critical path (work to regulate overall time) is unclear.
• There is no logical base for cycle-setting.
• Improvement work for cycle extension is insufficient.
• Study of time reduction is not implemented
Solving these problems, one by one, will lead to the reduction of shutdown time and cycle-time extension.
• This is equipment –related loss, wherein the equipment is “scheduled” to be kept under downtime due to certain permitted reasons.
• This loss is sub classified as follows.
• JH activity time
• PM activity time
• Meetings
• Development time
• Not scheduled at all
Mostly this loss will affect only OPE.
7. DEFECT & REWORK LOSS
Defect/rework losses are defined as volume losses due to defects and rework (disposal defects), and time losses required to repair defective products to turn them into excellent products.
Generally, sporadic defects are easily fixed, so they are rarely left uncorrected. Chronic defects, in contrast, are often left as they are, because their causes are difficult to perceive and measures to correct them are seldom effective. Rework and repair items are also regarded as chronic defects, because modification worker-hours are required This loss affects Quality Rate, OEE & OPE
Generally, sporadic defects are easily fixed, so they are rarely left uncorrected. Chronic defects, in contrast, are often left as they are, because their causes are difficult to perceive and measures to correct them are seldom effective. Rework and repair items are also regarded as chronic defects, because modification worker-hours are required This loss affects Quality Rate, OEE & OPE
6. SPEED LOSS
These are losses that occur because the equipment speed is slow. They can be defined as follows:
• Losses due to a difference between the design speed (or standard speed for the item concerned) and the actual speed
• Losses caused when the design speed is lower than present technological standards or the desirable condition
As an example of the first type of losses, if the standard cycle time is set at 40 seconds, and the actual operation time is 50 seconds, the speed loss is 10 seconds.
As an example of the second type of losses, if the set cycle time is 60 seconds, but it could be shortened to 50 seconds based on current-level improvements, the speed loss is 10 seconds.
Reasons for speed loss
-We mistakenly believe that the current machine cycle time is normal.
-We must slow down the machine cycle time to avoid problems.
-The equipment was poorly designed .
Reduction of Speed Loss
– Capacity balance of each process
– Actual cycle time measurement
– Reduction of cycle time
– Problem analysis for cycle time w.r.t. part quality.
• Losses due to a difference between the design speed (or standard speed for the item concerned) and the actual speed
• Losses caused when the design speed is lower than present technological standards or the desirable condition
As an example of the first type of losses, if the standard cycle time is set at 40 seconds, and the actual operation time is 50 seconds, the speed loss is 10 seconds.
As an example of the second type of losses, if the set cycle time is 60 seconds, but it could be shortened to 50 seconds based on current-level improvements, the speed loss is 10 seconds.
Reasons for speed loss
-We mistakenly believe that the current machine cycle time is normal.
-We must slow down the machine cycle time to avoid problems.
-The equipment was poorly designed .
Reduction of Speed Loss
– Capacity balance of each process
– Actual cycle time measurement
– Reduction of cycle time
– Problem analysis for cycle time w.r.t. part quality.
5. Minor stoppage & idling losses
The definition of these losses is as follows:
• Losses that are accompanied by temporary functional stoppage
• Losses allowing functional recovery through simple measures
(removal of abnormal work pieces and resetting)
• Losses that do not require parts exchange or repair
• Losses that require from 3-5 seconds to less than 5 minutes for recovery.
Unlike failures, minor stoppage/idling losses represent the condition in which equipment stops or idles because of temporary problems; for example, a work piece clogs a chute, or a sensor is triggered by a quality defect, temporarily stopping the machine. In this case, if the work piece is removed and resetting is done, the machine will operate normally. Thus, this condition is different in character from equipment failure
This loss affects Performance Rate, OEE & OPE
GENERAL PROBLEMS ON MINOR STOPPAGES
• Efforts to actualize as losses are not sufficient.
• Actions taken are poor
- Only emergency measures are taken as temporary measures.
• Phenomena are not discerned fully.
• Obstruction to un-attended operation.
- Operators are used for restoration.
- Minor stoppages keep operators from operating multiple stations or machines.- One minor stoppage will ruin the effects of unattended operation during breaks
• Losses that are accompanied by temporary functional stoppage
• Losses allowing functional recovery through simple measures
(removal of abnormal work pieces and resetting)
• Losses that do not require parts exchange or repair
• Losses that require from 3-5 seconds to less than 5 minutes for recovery.
Unlike failures, minor stoppage/idling losses represent the condition in which equipment stops or idles because of temporary problems; for example, a work piece clogs a chute, or a sensor is triggered by a quality defect, temporarily stopping the machine. In this case, if the work piece is removed and resetting is done, the machine will operate normally. Thus, this condition is different in character from equipment failure
This loss affects Performance Rate, OEE & OPE
GENERAL PROBLEMS ON MINOR STOPPAGES
• Efforts to actualize as losses are not sufficient.
• Actions taken are poor
- Only emergency measures are taken as temporary measures.
• Phenomena are not discerned fully.
• Obstruction to un-attended operation.
- Operators are used for restoration.
- Minor stoppages keep operators from operating multiple stations or machines.- One minor stoppage will ruin the effects of unattended operation during breaks
4. START-UP LOSS
Start-up losses are defined as time losses from
• start-up after periodic repair,
• start-up after suspension (long-time stoppage),
• start-up after holidays,
• Start-up after lunch breaks.
to the time when it is possible to produce excellent products of reliable quality, free from machine problems (minor stoppages, small problems, and blade breakdown) in a specified cycle time operation, as well as volume losses (defects/ rework) that arise during that period.
• Method of reducing start-up losses
– Time-series data at the time of start-up
– Examination of working oil/lubricating oil
– Examination of related equipment portions
– Adjustment of thermal displacement occurrence portions.
– Measurement of thermal displacement values
– Countermeasures
• start-up after periodic repair,
• start-up after suspension (long-time stoppage),
• start-up after holidays,
• Start-up after lunch breaks.
to the time when it is possible to produce excellent products of reliable quality, free from machine problems (minor stoppages, small problems, and blade breakdown) in a specified cycle time operation, as well as volume losses (defects/ rework) that arise during that period.
• Method of reducing start-up losses
– Time-series data at the time of start-up
– Examination of working oil/lubricating oil
– Examination of related equipment portions
– Adjustment of thermal displacement occurrence portions.
– Measurement of thermal displacement values
– Countermeasures
4. START-UP LOSS
Start-up losses are defined as time losses from
• start-up after periodic repair,
• start-up after suspension (long-time stoppage),
• start-up after holidays,
• Start-up after lunch breaks.
to the time when it is possible to produce excellent products of reliable quality, free from machine problems (minor stoppages, small problems, and blade breakdown) in a specified cycle time operation, as well as volume losses (defects/ rework) that arise during that period.
• Method of reducing start-up losses
– Time-series data at the time of start-up
– Examination of working oil/lubricating oil
– Examination of related equipment portions
– Adjustment of thermal displacement occurrence portions.
– Measurement of thermal displacement values
– Countermeasures
• start-up after periodic repair,
• start-up after suspension (long-time stoppage),
• start-up after holidays,
• Start-up after lunch breaks.
to the time when it is possible to produce excellent products of reliable quality, free from machine problems (minor stoppages, small problems, and blade breakdown) in a specified cycle time operation, as well as volume losses (defects/ rework) that arise during that period.
• Method of reducing start-up losses
– Time-series data at the time of start-up
– Examination of working oil/lubricating oil
– Examination of related equipment portions
– Adjustment of thermal displacement occurrence portions.
– Measurement of thermal displacement values
– Countermeasures
3. CUTTING BLADE (TOOL) CHANGE LOSS:
These are time losses due to regular cutting-blade exchanges and extraordinary replacement necessitated by blade damage and volume losses (defects and rework) that arise before and after blade replacement.
Cutting-blade losses are dropping due to material and shape studies yielding longer blade life, but they still pose a problem requiring further study.
In the case of transfer machines, cutting- blade losses may account for 10% to 12% of overall efficiency impedance, because the number of operators is few in relation to the number of the machines.
The reduction of cutting-blade losses requires study in both the fields of relevant technology (material changes, shape alteration, etc.) and software (vibration measurement and pursuit of optimum cutting conditions). The target is the maximisation of blade life
Methods of reducing cutting - blade losses
– Actual - state surveys
– Surveys of present cutting conditions
– Surveys of equipment/Jig precision
– Approach from inherent technology
– Approach from the vibration analysis
– Implementation of countermeasures
• This loss affects Availability ,OEE & OPE
Cutting-blade losses are dropping due to material and shape studies yielding longer blade life, but they still pose a problem requiring further study.
In the case of transfer machines, cutting- blade losses may account for 10% to 12% of overall efficiency impedance, because the number of operators is few in relation to the number of the machines.
The reduction of cutting-blade losses requires study in both the fields of relevant technology (material changes, shape alteration, etc.) and software (vibration measurement and pursuit of optimum cutting conditions). The target is the maximisation of blade life
Methods of reducing cutting - blade losses
– Actual - state surveys
– Surveys of present cutting conditions
– Surveys of equipment/Jig precision
– Approach from inherent technology
– Approach from the vibration analysis
– Implementation of countermeasures
• This loss affects Availability ,OEE & OPE
Setup & adjustment loss
of Change-over times.
Where ever possible, externalize!
1. Preparation
1) What can be prepared prior to set-up?
All necessary jigs, tools and parts stored on a dedicated “change-over trolley” - Can we color code such items for different products/pack sizes ?
2) Move hands, but do not move feet.
Set-up :
1) We hate bolts! Bolts are the enemy!
Minimize number of bolts - Examine requirement of bolts
Minimize types of bolts - Standardize bolts so that it reduces the number of tools required to unfasten it Minimize amount of thread Loosen, not unfasten Minimize repositioning of spanner on bolt head whilst undoing or tightening. Use tools that don’t require repositioning (wing nuts, ratchets etc)
Boltless construction - one touch (clamps, cams, plungers etc)
- no touch (mechanize)
2) Minimize number of change-over parts (convert to modular type)
3) Standardize jigs and tools
4) Improvements to make simultaneous change-over possible
5) Improve standardization of set-up procedures - Make Multiple activity chart.
6) Optimize ratio between amount of work and number of people
7) Practice set-up procedures (increase skill levels)
Adjustments :
1) Mechanization
2) Simplification of work - mark set values on scales, use block gauges, spacers, stops etc.
3) Use visual controls
4) Clearly identify and maintain datum faces - eliminate dirt, wear, damage, rust etc.
5) Do not move die and jig reference stops.
6) Improve work practices - procedures, tools etc
7) Practice adjustment work - increase skill level
Failure Losses
There are two types of failure loss
Loss no.1A : Equipment failure loss
Loss no.1B : Breakdown loss
This loss is expressed in time
Loss no.1A is the time lost by the equipment due to a breakdown involving the replacement of spare parts.
Loss no.1B is the time loss by the equipment due to a Breakdown not involving any replacement of spare parts.
Since zero breakdowns is our objective, target for this loss is zero.
This loss affects
Availability, OEE and OPE.
Loss no.1A : Equipment failure loss
Loss no.1B : Breakdown loss
This loss is expressed in time
Loss no.1A is the time lost by the equipment due to a breakdown involving the replacement of spare parts.
Loss no.1B is the time loss by the equipment due to a Breakdown not involving any replacement of spare parts.
Since zero breakdowns is our objective, target for this loss is zero.
This loss affects
Availability, OEE and OPE.
16 MAJOR LOSSES
• EQUIPMENT FAILURES
• SETUP & ADJUSTMENT
• CUTTING BLADE ( TOOL ) CHANGE
• START-UP
• MINOR STOPS
• REDUCED SPEED
• DEFECT & REWORK
• SCHEDULED DOWN TIME
• MANAGEMENT
• OPERATING MOTION
• LINE ORGANISATION
• LOGISTICS
• MEASUREMENT & ADJUSTMENT
• YIELD
• ENERGY
• TOOL DIE AND JIG
• SETUP & ADJUSTMENT
• CUTTING BLADE ( TOOL ) CHANGE
• START-UP
• MINOR STOPS
• REDUCED SPEED
• DEFECT & REWORK
• SCHEDULED DOWN TIME
• MANAGEMENT
• OPERATING MOTION
• LINE ORGANISATION
• LOGISTICS
• MEASUREMENT & ADJUSTMENT
• YIELD
• ENERGY
• TOOL DIE AND JIG
KOBETSU KAIZEN
Objective:
-Understand losses
-Ability to calculate OEE and reduce losses by kaizens
-Reduce manufacturing cost by carrying out kaizens
Aim : Realising for high production efficiency by eliminating
16 major losses
Method: Recognition of 16 major losses
Over all equipment efficiency, material, die, jig, tool and energy req.
per unit calculation and setting targets for the above.
Analysis of phenomenon and review of the associated factors
Execution of PM analysis
Through pursuit of “what the equipment and production must be”
Who : Staff and cell leaders
This pillar pursues efficient equipment, worker, material and energy utilization that is extremes of productivity and aims at achieving substantial effects.
This pillar works on reducing / eliminating the 16 major losses. The basis of these activities is to enhance and demonstrate the technological, analytical and kaizen powers of the engineers & operators engaged in these activities.
-Understand losses
-Ability to calculate OEE and reduce losses by kaizens
-Reduce manufacturing cost by carrying out kaizens
Aim : Realising for high production efficiency by eliminating
16 major losses
Method: Recognition of 16 major losses
Over all equipment efficiency, material, die, jig, tool and energy req.
per unit calculation and setting targets for the above.
Analysis of phenomenon and review of the associated factors
Execution of PM analysis
Through pursuit of “what the equipment and production must be”
Who : Staff and cell leaders
This pillar pursues efficient equipment, worker, material and energy utilization that is extremes of productivity and aims at achieving substantial effects.
This pillar works on reducing / eliminating the 16 major losses. The basis of these activities is to enhance and demonstrate the technological, analytical and kaizen powers of the engineers & operators engaged in these activities.
KOBETSU KAIZEN
Objective:
-Understand losses
-Ability to calculate OEE and reduce losses by kaizens
-Reduce manufacturing cost by carrying out kaizens
Aim : Realising for high production efficiency by eliminating
16 major losses
Method: Recognition of 16 major losses
Over all equipment efficiency, material, die, jig, tool and energy req.
per unit calculation and setting targets for the above.
Analysis of phenomenon and review of the associated factors
Execution of PM analysis
Through pursuit of “what the equipment and production must be”
Who : Staff and cell leaders
This pillar pursues efficient equipment, worker, material and energy utilization that is extremes of productivity and aims at achieving substantial effects.
This pillar works on reducing / eliminating the 16 major losses. The basis of these activities is to enhance and demonstrate the technological, analytical and kaizen powers of the engineers & operators engaged in these activities.
-Understand losses
-Ability to calculate OEE and reduce losses by kaizens
-Reduce manufacturing cost by carrying out kaizens
Aim : Realising for high production efficiency by eliminating
16 major losses
Method: Recognition of 16 major losses
Over all equipment efficiency, material, die, jig, tool and energy req.
per unit calculation and setting targets for the above.
Analysis of phenomenon and review of the associated factors
Execution of PM analysis
Through pursuit of “what the equipment and production must be”
Who : Staff and cell leaders
This pillar pursues efficient equipment, worker, material and energy utilization that is extremes of productivity and aims at achieving substantial effects.
This pillar works on reducing / eliminating the 16 major losses. The basis of these activities is to enhance and demonstrate the technological, analytical and kaizen powers of the engineers & operators engaged in these activities.
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