Abstract:
Today, material management has gained acceptance in all developing economics. As
material is nothing but money in the form of goods, each industry uses materials for its
smooth running. A Power Plant is a public-interest company. Electricity plays a very'
important role in regulating modern Ii lii. Therefore, any interruption in the supply Of this
vital itcm of energy puts the whole system out of gear and paralyses our life. It uses various
types of materials for smooth running. Raw materials and consumables are being
converted into work-in-progress and finally produce electricity for national grid. Spare
parts and components are utilized for the smooth functioning of the production
machineries. This necessitates the involvement of the finance executives with the policy-
appropriate management system of spare parts for schedule maintenances is developed in this research.
making of the materials function. So, an This research work is an outcome of scientific spare parts management policy required for schedule maintenance of a Barge Mounted Power Plant, Bangladesh. The materials department accounts for over 60 percent of the cash outflows and 90 percent of working
capital in the Plant [4]. The Logistics Department is responsible for managing all types of
materials in the Plant. The functions of procurement, materials management, business
logistics, inventory control and warehousing are being carried out in the Plant under the
scope of integrated materials management. The Plant follows various procedures to manage
its materials. But the management does not follow any analytical procedure in setting up
reorder points. As a result, the Plant faces over-stocking of spare parts in the warehouse.
This situation acts as a catalyst to increase the total expenditure of the Plant. By applying
scientific materials management method it has been calculated reorder points, safety stock
and order quantity of spare parts of schedule maintenance which eventually reduced
overstocking as well as overall cost.
The Plant gets an idea of annual power demand from BPDP. Based on BPDP's power
demand, Operation department determines annual plant factor and Maintenance department
makes annual maintenance schedule depending on plant factor. Logistics converts number
of schedule maintenance into annual spare parts demand and review period spare parts
demand and places orders accordingly. The strategy of logistics department is to review the
inventory position in the first week of every month (i.e. review period R=one month=30
days) and places order of those items which are at or below the reorder point depending on
the demand of planning period (lead time + review period). If the position is above reorder
point, nothing is done until the next review period. So, the Plant more or less follows (R,s,S
- Periodic-review, recorder point, order- up-to-level) system. Theoretically, (R,s,S) system
is appropriate when tight control is necessary, e.g. for class A items. Reorder point is the
base-stock of the system. Relying on a reorder point replenishment actions are taken. But
the Plant uses the (R,s,S) system for all type of spare parts to show a high degree of
responsiveness to meet demand rate. Reorder point answers the question when to order in
the system. Applying (R,s,S) system actual reorder points, safety stock and ordered
quantity of schedule maintenance parts are determined in this thesis (chapter 4).
Lead time is an important factor in placing an order. The order quantity depends on lead
lime. The Plant's calculated lead time is 90 days (chapter 3) and review period is 30 days.
So, the Plant can place maximum three orders in a year. For lengthy lead time, it has to
place order of large quantity. In the obtained data of previous year, it has been observed
that the Plant's tendency is to bring yearly demand by placing two or a single order. In this
research work, it has been shown that three orders can meet yearly variable demand easily.
It reduces holding cost but increases ordering cost in the Plant. As ordering cost mostly
depends on the salary of the employee of the purchase department, so ordering cost per
order is almost constant in the Plant. If for a given period actual demand is less than
expected, extra inventory is left over, which increases the holding cost. Therefore, there is
no reason in decreasing ordering cost. The calculated holding cost in the Plant is 66% of unit value of an item and ordering cost is $25/order/item chapter 3). Holding cost plays a vital role in increasing or decreasing of total incremental cost. The objective of this research was to reach a balance between the extra holding cost and the ordering cost.
In the obtained data, it is observed that 122 (one hundred twenty two) items are required to
execute all schedule maintenances. ABC classification has been carried out in this research
to find out key components (chapter 3). Out of 122 (one hundred twenty two) items only
14(fourteen) items are graded as class A items. But all items are equally important from
maintenance point of view. With shortage of any item the maintenance task cannot be done
Successfully. So, from maintenance point of view all 122 (one hundred twenty two) items
are regarded critical. In the thesis work, annual demand, lead time demand and review
period demand of various spare parts required for schedule maintenance are determined
based on maintenance schedules to be carried out in whole year. Demand is the output of
inventory control system. So it is more emphasized on demand calculation. After demand
calculation, reorder point, safety stock and ordering quantities have been analytically
calculated.
Calculated total incremental cost is compared with the data of previous year (chapter 4), it
is found that most of the low valued (class C) items are having lower holding cost than
ordering cost. So, total incremental cost of these items becomes lower. Again, there is no
benefit in decreasing ordering cost for C class items in the Plant. On the contrary, reducing
holding cost, it is shown in this research that the total incremental cost of 2006 is 1.70%
lower than previous year after covering extra 5% plant factor and more 19 schedule
maintenance (in 2006 plant factor was 75% with 222 maintenance and in 2005 plant factor
was 70% with 203 maintenance) of which (19 maintenance) total incremental cost is USD
21,938.08. If this value is deducted from existing figure then it becomes 10.12% lower in
comparison with previous year. Total inventory cost is not compared because it is largely
influenced by purchase cost.
The Materials Requirement Planning (MRP) may act as a bridge between Logistics and
Maintenance department. But, the Plant does not maintain MRP. As a result, it has to face
communication gap among the departments. MRP of 1 500hrs. maintenance is shown in this
research as a sample.
All the data available in the Plant are deterministic. It may change due to the change of
power demand of BPDP.