Spares criticality assessment methods & equipment overhaul replacementrepairs procedures
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Transcript of Spares criticality assessment methods & equipment overhaul replacementrepairs procedures
Spares critically assessment method &equipment
overhaul/replacement/repairs procedure
Muhammad amirul faiz b amil azman Ec11127
Muhamad faiz b azman Ec11128
Nurfarah athirah bt azmi mukhtarEc11125
Nurul nadia bt ibrahimEc11060
Spares Parts
is an interchangeable part that is kept in an inventory and used for the repair or replacement of failed parts.
an important feature of logistics management and supply chain management, often comprising dedicated spare parts management systems.
Example :- Cars(e.g.. Tires)
Criticality Assessment
Criticality analysis is a method for identifying product or process criticality for the purpose of prioritizing activities like design and maintenance
Criticality is the combined measure of the failure mode probability and the severity of its effects.
Spare Criticality Assessment
It has been observed in many industries that the non-availability of spare parts, as and when required for repairs, contributes to as much as 50% of the total down time
Classification of Spare Parts
1. Critical spares - without a substitute -with long procurement lead time - with a high failure rate - without which the machine can’t be operated even in suboptimal efficiency
Classification of Spare Parts
2. Non critical spares -that have substitutes -that can be made / purchased in short notice - that have high reliability - without which machine can run
Models for Type of Spares
Non-repairable Spares
Parts which fail can’t be repaired and must be replaced with a new parts
Models for Type of Spares
Repairable Spares
Parts which fail can be repaired and be used back as spares
Assessment Method
Analytic hierarchy process find out relevant factors of the critical spare parts
and determine the relative importance Grey prediction model find a sequence of each element corresponding to
future dynamism, thereby developing prediction model
Back-propagation network used as a tool for judging the predictability Moving average method The moving average (MA) is the mean of the previous
data sets used to perform CSP demand prediction
Assessment Method
Management of Spare Parts
The objective of spare parts management is to ensure the availability of spares for maintenance and repairs of the plant and machinery as and when required at an optimum cost.
Need a proper planning and control of spare parts inventory.
Identify requirement
Procure parts
Initiate replacement process
Reorder part replacements
Complete administrative tasks
Identify requirement
Each holding location is checked as to needs
Standard procedures and relevant documentation is obtained
Current holdings are monitored and checked against levels determined by procedures
Procure parts
Checks are made as to
extra holdings in other locations
Requests for additional parts
are made in accordance
with enterprise procedures
Current holdings are
matched with need
Initiate replacement process
• Need for spare parts is determined
• Data base is activated to check possible location of specific parts required
• Arrangements are put in place to deploy the part to the site where it is required
• Part is changed over with the faulty part
• Faulty part is recovered and disposed of or returned for repair as determined by condition and enterprise policy
Relevant part request
(forms/documentation) is completed and forwarded to
the vendor
Delivery of replacement is
followed up on a regular and ongoing
basis (eg: phone call)
Alternate spares are sought where
difficulties (delay/no stock) are
experienced with replacement
Reorder part replacement
Complete administrati
ve tasks
Regular audit of stock holdings is
conducted in accordance with enterprise policy
Checks are made to ensure that all parts are latest issue and are
compatible with installed systems and equipment
Relevant documentation is
completed, signed and
forwarded to the appropriate area
inventory
Inventory is the total
amount of goods and/or
materials contained
in a store or factory at any given
time.
Helps us know the precise
number of items on
the shelves and storage
areas in order to
place orders or control losses
Inventory analysis
Commonly used:
(1) FSN Analysis (2) HML Analysis (3) VED Analysis
FSN analysisFast Moving
(F) : Items that
are frequently issued say more than
once a month.
Slow Moving (S) :
Items that are issued less than once a month
Non-Moving (N) :
Items that are not
issued\used for more
than 2 years.
HML analysis
High Cost (H) : Item whose unit value is
very high
Medium Cost (M) :
Item whose unit value is of medium
value
Low Cost (L) : Item whose unit value is
low
H M L
VED analysisVITAL (V) : A spare part will be termed vital, if on account of its non-availability there will be very high loss due to production downtime and/or a very high cost will be involved if the part is procured on emergency basis. In a process industry, most spare parts for the bottleneck machine or process will be of vital nature.For example, bearings for a kiln in a cement plant will be considered vital.
ESSENTIAL (E) : A spare part will be considered essential if, due to its non-availability, moderate loss is incurred. For example, bearings for motors of auxiliary pumps will be classified as essential.
DESIRABLE (D) : A spare part will be desirable if the production loss is not very significant due to its non-availability. Most of the parts will fall under this category. For example, gaskets for piping connection
DefinitionProcess of restoring and maintaining an equipment, machine , or system in a serviceable condition.
Overhaul involves: - partial or complete disassembly of the item, - inspection to detect damaged, defective, or worn parts, - repair or replacement of such parts- reassembly, testing, and trial-run prior to returning the item to its full operating level
overhaul
Classes of Overhaul Work There are five classes of equipment overhaul (A, B, C, D, and E). The class defines the type and scope of work to be done on each equipment by the overhauling activity. (Do not confuse equipment overhaul with the term regular overhaul.)
CLASS A OVERHAUL.—A class A overhaul includes overhaul, repair, and/or modification; for example a modification could be an Ordnance Alteration (ORDALT), Special Program Alteration (SPALT), Ship Alteration (SHIPALT), or a field change that will sustain or improve the performance of a system or component to meet its most-recent design and technical specifications. The end product should be like new in appearance and operation.
CLASS B OVERHAUL.—A class B overhaul includes overhaul and repair that will restore the performance of a system or component to its original design and technical specifications. Modifications or alterations are not done unless specified by the customer.
CLASS C OVERHAUL.—A class C overhaul includes only repair work on a system or component specified by a work request or work required to correct malfunctions specified by the customer.
CLASS D OVERHAUL.—A class D overhaul includes work related to the open, inspect and report type of work request. It is intended to be diagnostic in nature and may require various tests. It is normally associated with preoverhaul test and inspection (POT& I).
CLASS E OVERHAUL.—A class E overhaul includes work required to incorporate all alterations or modifications specified for a system or component.
replacementDefinition A person or thing that take a place
of another esp. of one that has worn out, broken down,etc
WHY NEED REPLACEMENT?? The cost for repair the equipment is more
expensive than the cost to replace the new equipment.
Equipment reach it life-cycle to work efficiently. At that time the overhaul procedure is no useful.
Increasing operational effectiveness when the equipment was replace with new equipment even at the first, higher initial investment are required.
When the equipment presents an unacceptable safety risk to the plant, plant personnel or the environment
Not meet the specification required by customer. Means that the quality of the product produced at low quality
examples coffee roaster(Main Fan Replacement)
To start, remove the Heat Guard Grills and Main Filter as indicated in this image by the green arrows. Loosen all four Phillips head screws (red arrows) which hold the fan in place. Hold the fan against the machine when removing the last screw.
Lower the fan, but take care not to stress the wires.
Carefully pull the connector through the back of the machine. Grasp the two halves of the polarized connector and wiggle them while pulling to separate them. As seen here, the connector will only go back together in one way.
When replacing the fan push the wires and connector through the back of the machine, and place the wires as shown here. Be sure not to pinch the wires when replacing the fan. Hold the fan in place, be sure that it is aligned all the way around and that the wires are not pinched, and then loosely replace all for screws before tightening them. Do not over-tighten the screws!
Repairs procedures
Definition Set of rules according to which actions
are generated in the repair order. It is assigned in customizing to the item
categories that are relevant for repairs processing and is adopted in the repair request item in the repair order.
CATEGORY AND PRIORITY
DEFINITION RESPONSE TIME
1 Emergency Failures or defects causing or likely to cause widespread disruption, injury to person, serious damage to the building, fabric, services, equipment or property.Emergency works take priority over all other categories of work.
Within 2 hours
2 Urgent Failures or defects which do not present a serious risk of damage or injury, but will cause considerable disruption and inconvenience.
Within 24 hours
3 Routine(High priority)
Normal repairs which are unlikely to cause a high degree or inconvenience or risk to any persons or property
Within 7 days maximum
4 Routine(Low priority)
Within 21 days maximum
5 Cylical(Planned routine)
As described in 3 and 4 above but can differed to enable work to be batched and planned on regular basis
Within 6 weeks