8 Availability Losses
Breakdown loss (failure losses)
Losses due to failures. Type of failure include sporadic function stopping failures and function – reduction failure in which the function of the equipment drop below normal levels like replacement of parts and repair, cases requiring 5 minute or more for repair.
Target is zero failures
To attain zero failure, it is necessary to correct the misconception about breakdown maintenance that failures are unavoidable
Planned Maintenance Time Loss (Shut Down Loss)
Time when equipment is shut down for maintenance. However shut down related work generally affect the operating time rate of equipment. Shutdown related work must be regarded as a loss and reduction of shutdown work time must be sought.
e.g. Change of Dies, machining fixtures etc.
Setup and adjustment losses refers to time losses from the end of the production of a previous items through product – change adjustment to the point where the production of the new item ic = s completely satisfactory. SMED must. Adjustments how to reduce, eliminate? One slot adjustment or trial or error till 3-4 components is tried.
Tool Change Loss / cutting blade losses
e.g. Change of Drill, tap, rammer, cutter etc.
Stoppage losses caused by changing the cutting blade due to breakage or caused by changing the cutting blade when the service life of the grinding stone, cutteror bites has been reached
What is your tool change loss? 5 or > 10 %.
Normally a fix number of time is set but if the tool breaks before that – it leads to change, adjustment and a new sort over all again.
Start up Loss
e.g. furnace, paint shop oven etc.
Start up losses are define 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
When starting production, the losses that arise until equipment starts up, running and production processing conditions stabilize.
Do your machines have ‘Monday Disease?
Minor stoppage loss
i.e. Frequent stoppage for short time from seconds to less than 5 minutes for recovery
e.g. Component stuck to die while stamping etc.
Losses that occurs when the equipment temporarily stops or idles due to sensor actuation or jamming of the work The equipment will operate normally through simple measures (removal of the work and resetting)
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 part exchange or repair
To reduce minor stoppage, it is important to adequately analyze the phenomena involved and thoroughly eliminate minor defects. The target number of minor defects is zero.
Reduce speed loss
e.g. 50 parts produced against standard of 53 parts as a cycle time increased to 9 min from 8.5 due to less speed/feed
These are losses that occur because of 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 design speed is lower than present technological standards or the desirable conditions
If the design speed is 60 seconds and actual cycle time is 65 seconds then the loss is 5 seconds.
The target is to reduce the difference between design speed and actual speed to zero
Defects and rework
i.e. any reworked or rejected product shows direct time loss due to poor quality
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 to realize zero defects, it is necessary to radically review defective phenomena.
5 major losses that impede workers efficiency
Losses impeding human efficiency
e.g. Row material/ persons not available esp. poor planning.
Waiting losses that are caused by management, such as waiting for material, waiting for a dolly, waiting for tools, waiting for instructions, waiting for repairs of breakdowns, etc.
Operating Motion Loss (OML)
e.g. Excess motion like walking, bending, stretching etc.
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.
Adjustment & Measurement loss
e.g. Frequent tool adjustment after few components.
Work losses from frequent measurement and adjustment in order to prevent the occurrence and outflow of quality defects.
Line organization loss (LOL)
e.g. 75% manpower utilization due to poor line balancing
These are waiting time losses involving multi – process and multi stand operators and line balance work in conveyor work
Logistics loss/ distribution losses/ losses resulting from failure to automate.
e.g. operator travels/ waits for want of material on stage.
Distribution man hour losses due to transport of materials products (proceed products) and dollies.
These are also personal losses resulting from non replacement with automated systems, although such replacement could be done. They include for instance case in which automated loading and unloading leading to manpower reduction is not implemented, although it could be done.
Losses of costs – three major losses that sat can impede effective use of production resource
3 major losses that impede efficient use of production subsidiary resources
Losses of cost
e.g. losses due to heat radiation, leakage of fuel, air, oil, losses, due to ineffective utilization of input energy (electric, gas, fuel oil, steam, air and water etc) in processing . Etc.
Because of electricity, fuel, utility cost represents a high percentage of the total cost, all companies are striving to reduce them
Die/ Tool loss
e.g. lose of tool due to regrinding, poor life of molds etc, repairs of Dies/ Tools FOS consumables
These are monetary losses resulting from the mfg and repair of dies, jigs and tools necessary for the production of products
Mfg new modules, replacement at the end of service life, breakdown, repair is expensive.
To reduce mfg costs it is absolutely necessary to extend MTBF of mould repair, to prevent product breakage and to extend the service life of replacement parts
e.g. Excess material stock/ weight, Exclusive splashes etc…Material losses due to differences in the weight of the input materials and the weight of the quality products.
Increase casting wall thickness to avoid below holes leading to more machining time and loss of material.
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