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