maintainence technology

1. SPARES CRITICALITY
ASSESSMENT METHOD
Group Members
Kelvin Lazarus
Kong Chiou Shin
Loh Vuan Yee
Hou Xiao Ming

2. What are Spares Parts
 Spare parts are extra parts that are near to a
functioning part
 When a machine has problems, spare parts
can be used to replace broken /damaged parts
so that the machine can function.
 Example :-
 power module (eg. Transformer)
 Electronic parts (eg. Integrated components / semi-
conductors and etc.

3. What is Criticality Assessment
 Give an indication of which items of plant are
most critical to your process.
 Good idea to do a criticality assessment so
everybody involved on your plant knows how
crucial any single item of plant is to the
process and how quickly to act when
diagnosed an impending failure.

4. What is Spare Criticality
Assessment
 Spare Critically Assessment plays an
important role in achieving the desired plant
availability at an optimum cost
 Downtime for such plant and machinery is
prohibitively expensive
 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

5. Classification of Spare Parts
1. Critical spares
 without which the machine can’t be operated even in
suboptimal efficiency
 with a high failure rate
 with long procurement lead time
 without a substitute
 used in critical machines (identified for preventive
maintenance)
2. Non critical spares
 without which machine can run (at least sub optimally)
 that have high reliability
 that can be made / purchased in short notice
 that have substitutes
 available off shelf as standard parts (bearings etc.)

6. Models for Type of Spares
 Non-repairable Spares
 Partswhich fail can’t be repaired and must be
replaced with a new parts

7. Models for Type of Spares
 Repairable Spares
 Parts
which fail can be repaired and be used back
as spares

8. Assessment Method
 Analytic hierarchy process
 findout 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

9. Assessment Method

10. Management of Spare Parts
 Proper planning and control of spare parts
inventory.
 Eg: Material forecast planning, Asset
recovery services, Equipment receiving and
staging, Equipment tracking and reporting.

11. How To Manage Spare Parts
1. Identify requirement
 Standard procedures and relevant
documentation is obtained
 Current holdings are monitored and checked
against levels determined by procedures
 Each holding location is checked as to needs

12. How To Manage Spare Parts
2. Procure parts
 Current holdings are matched with need
 Requests for additional parts are made in
accordance with enterprise procedures
 Checks are made as to extra holdings in other
locations

13. How To Manage Spare Parts
3. 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

14. How To Manage Spare Parts
4. Reorder part replacements
 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

15. How To Manage Spare Parts
5. Complete administrative tasks
 Relevant documentation is completed, signed
and forwarded to the appropriate area (eg:
Account Payable - Boucher, Account Receivable
– receiving documentation, Filing and Retention
document – filing history)
 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

16. 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

17. Inventory Analysis
 Commonly used inventory analyses are:
 (1) FSN Analysis
 (2) HML Analysis
 (3) VED Analysis

18. Inventory Analysis
 FSN Analysis
 Fast 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 issuedused for
more than 2 years.
 Help establishing most suitable stores layout by
locating all the fast moving items near the
dispensing window to reduce the handling efforts

19. Inventory Analysis
 HML Analysis
 HighCost (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
 Efforts may be necessary to find out the
means for prolonging the life of high value
parts through reconditioning and repair

20. Inventory Analysis
 VED Analysis
 VITAL (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.

21. The End