14 ) WCM- Inventory Flashcards
What is the inventory balancing act?
Liquidity vs profitability
L- Reducing inventory to the lowest possible amount to minimise the level of capital employed to be funded
P- Ensuring that sufficient inventory is held so that it does not run out and disrupt business
What are the costs of low levels of stock?
▪ Increased chances of stock outs (Particular product used in manufacturing)and as a result lost contribution, sales, production stoppages (Idle time, stockpiling of WIP), emergency order of more expensive or poorer quality supplier
▪ High re-order/setup costs as you will need to stock frequently resulting in high order and delivery costs
▪ Lost quantity discounts- Bulk discounts are missed
What are the costs of high levels of stock?
▪ Tied up capital- capital is tied until it is sold. The lost return is an opportunity cost
▪ Financing cost - high levels in stock need to be financed by means of overdraft/loan and the interest will be payable on the financing used.
▪ Holding costs of storage, insurance, managing, risk of theft / damange /obsolesence and the net realisable value being lower than the cost
What is the objective of good inventory management?
i.e. what must be determined in order to have a good management
To determine the:
▪ the optimum re-order level – how many items are left in inventory when the next order is placed, and
▪ the optimum re-order quantity – how many items should be ordered when the order is placed
What is lead time?
The lag between when an order is placed and the item is delivered
What is buffer inventory?
the basic level of inventory kept for emergencies. A buffer is required because both demand and lead-time will fluctuate and predictions can only be based on best estimates.
What is the economic order quantity?
the aim and how does it accomplish this
This is an optimum order quantity for inventory for businesses that do not use JIT inventory management system.
The aim of EOQ model is to minimise the total cost of holding and ordering inventory. It does this by balancing the variable costs of holding the inventory and the fixed costs of placing the order
What is the relationship between the reorder quantity and holding costs?
It is linear. As the re order quantity increases, the holding cost increases
What is the relationship between the reorder quantity and fixed costs?
As the number of re order quantity increases, the level of ordering cost increases
What are the assumptions for EOQ?
▪ Demand for inventory is constant- we’re using it up at a constant rate.
▪ lead time are constant and known. (means that the we assume the time between an order being placed and the date it is delivered is the same for every order) We can deal with this in the questions
▪ Purchase price is constant- (no change in the cost of purchasing new inventory
▪ No buffer inventory is held (not needed)- BECAUSE the demand is constant and we know the lead time, there is no need to hold buffer inventory
use this to discuss the validity of the model and it’s conclusions e.g. in practice, demand and/or lead time may vary
..How do you deal with bulk discounts?
Step 1: Calculate EOQ, ignoring discounts.
Step 2: If the EOQ is below the quantity qualifying for a discount, calculate the total annual inventory cost arising from using the EOQ:
Total annual inventory cost = purchase costs (D × P where P is purchase price) + ordering costs (CO × D/Q) + holding costs (CH × Q/2)
Step 3: Recalculate total annual inventory costs using the order size required to just obtain each discount. Take the available discount into account within the purchase costs.
Step 4: Compare the totals from steps 2 and 3 and select the lowest cost option.
Step 5: Repeat for all discount levels.
What is the re order level?
how is this calculated when two factors are known
After identifying how much to reorder, the next thing a company needs to figure out is what level of inventory level needs to be reached before an order is placed.
This is the quantity of inventory on hand when an order is placed.
When demand and lead time are known with certainty, the ROL may be calculated exactly i.e. = demand in the lead time
.What is the re order level when lead time and demand are known?
the ROL may be calculated exactly i.e. = demand in the lead time
.What is the re order level when lead time and demand are not known?
ROL = demand during lead-time.
Where there is uncertainty, an optimum level of buffer inventory must be found.
This depends on:
variability of demand
cost of holding inventory
cost of stockouts.
You will not be required to perform this calculation in the examination.
What are some inventory management systems?
Periodic review
Just in time
What is the periodic review system (Constant order cycle system)?
Inventory levels are reviewed at fixed intervals, e.g. every four weeks. The inventory in hand is then made up to a predetermined level, which takes account of:
likely demand before the next review
likely demand during the lead-time.
So for e.g. Thus a four-weekly review in a system where the lead time was two weeks would demand that inventory be made up to the likely maximum demand for the next six weeks.
.What is slow moving inventory? and what method can be used to help with this
Certain items may have a high individual value, but be subject to infrequent demand. Management need to review inventory usage to identify slow-moving inventory. An aged inventory analysis should be produced and reviewed regularly so that action can be taken.
For slow moving inventory, actions include?
Actions could include:
elimination of obsolete items
slow-moving inventory items only ordered when actually needed (unless a minimum order quantity is imposed by the supplier)
review of demand level estimates on which re-order decisions are based.
A regular report of slow-moving items is useful in that management is made aware of changes in demand and of possible obsolescence. Arrangements may then be made to reduce or eliminate inventory levels or, on confirmation of obsolescence, for disposal.
What is just in time system?
Some manufacturing companies have sought to reduce their inventories of raw materials and components as low as possible. This helps improve profitability by reducing financing costs.
JIT describes a policy of obtaining goods from suppliers at the latest possible time (i.e. only when they are needed in manufacturing)
What are the aims of just in time?
a smooth flow of work through the manufacturing plant
a flexible production process, which is responsive to the customer’s requirements
reduction in capital tied up in inventory.
AND This involves the elimination of all activities performed that do not add value = waste.
What is waste and the examples?
Waste is defined as any activity performed within a manufacturing company that doesn’t add value to the product. examples are:
raw material inventory WIP inventory finished goods inventory materials handling quality problems (rejects and reworks, etc.) queues and delays on the shop floor long raw material lead times long customer lead times unnecessary clerical and accounting procedures.
How does JIT attempt to eliminate waste at every stage of the manufacturing process?
notably by the elimination of:
WIP, by reducing batch sizes (often to one)
raw materials inventory, by the suppliers delivering direct to the shop floor JIT for use
scrap and rework, by an emphasis on total quality control of the design, of the process, and of the materials
finished goods inventory, by reducing lead times so that all products are made to order
material handling costs, by re-design of the shop floor so that goods move directly between adjacent work centres.
What does a JIT manufacturer look for in a supplier? and in return what can the supplier expect?
looks for a single supplier who can provide high quality, frequent and reliable deliveries, rather than the lowest price. In return, the supplier can expect more business under long-term purchase orders, thus providing greater certainty in forecasting activity levels. Very often, the suppliers will be located close to the company.
What does single sourcing and long term contacts achieve?
Long-term contracts and single sourcing strengthen buyer-supplier relationships and tend to result in a higher quality product. Inventory problems are shifted back onto suppliers, with deliveries being made as required.
How does JIT affect those in delivery and transportation?
Smaller, more frequent loads are required at shorter notice. The haulier is regarded as almost a partner to the manufacturer, but tighter schedules are required of hauliers, with penalties for non-delivery.
at the EOQ level, holding vost and ordering cost are?
equal
what is over capitalisation
excess inventory/receivables and cash - investment in WC is too high.
& Low payables
This means you have over invested (over capitalized) which will reduce profit.
what is over trading
where there is high growth and the business runs out of cash.
This arises from a lack of investment in working capita. the reason this happens is because the company is growing fast. It maybe hasn’t got the resources in place to manage the working capital properly so it all gets out of control.
so e.g. receivables are increasing significantly as a result of not having someone to chase people to get the money.
doesn’t mean the level of WC is low but it’s more the lack of investment in WC MANAGEMENT is missing/Goes wrong because they’re worried about other things.
what is the holding cost
FINANCE & storage/warehouse costs
what is the relationship between holding and ordering cost
inverse relationship.
If high inventory= High holding but low order
If low inventory= Low holding but high order
This relationship is where the EOQ is based on
what is the annual holding cost formula
and the formula for when working out the annual cost without the EOQ
(EOQ/2)*HOLDING COST
we’re going to be looking at the average position of the inventory (divide by 2) because one of the things we assume is that inventory is used up equally throughout the year at a constant rate (unrealistic).
when working out the total cost in general (without EOQ) use for the average demand make sure to include buffer
average demand = (buffer + max inventory) /2
what is the annual Ordering cost formula
Number of order (demand for inventory/ EOQ) * Cost per order
if given the buffer, what is used in the annual holdingn cost formula
average demand = (buffer + max inventory) /2
what is maximum inventory
buffer plus the inventory held (EOQ)
what is the total inventory cost?
Purchase Cost
holding cost
ordering cost
