stock control

types of stock

raw materials

work-in-progress

finished goods

buffer stock

is an emergency minimum level of stock held

holding buffer stock of finished goods - surges in demand

or - holding a buffer stock of raw materials

buffer stock protects against the risk of disrupted production & workers idling waiting for stock to arrive

disadvantages of holding high levels of stock

if selling fruits or vegetables they may become perished

more costs for the business such as: renting factories

fluctuations in demand - trends & behaviour

damage to property or theft - results in more costs

stock control chart

maximum stock level - largest amount of stock that can be held

re-order level - if stock falls to this level, firms will order more stock from the supplier. this level is reached before delivery, as the supplier needs to process the order

minimum stock level - aka buffer stock level, least amount of stock the firm wishes to keep

implications of poor stock control

opportunity cost - money is only used for stock and nothing else

cash flow problems - if stock isn't sold quickly - profits aren't maximised

increased storage costs - cost of warehousing, insurance, security

holding too little stock

firm cannot cope with surges in demand

result in loss of customers as they simply move to competitors

stopping production - idle labour

just in time

stock control system that operates with 0 buffer stock

advantages - reduced stock-holding costs

improved cash flow

reduced stock waste & more space in factories

disadvantages - unreliable suppliers (late delivery, poor quality)

no spare or finished goods meaning that the business cannot meet unexpected orders

kaizen - a japanese term for "continuous improvement" - making many small, gradual changes to improve either quality or efficiency


order quantity: the amount ordered each time

reality of stock control:
in reality stock control diagrams showing a neat pattern is not true. orders may arrive late and may not be of the correct quantity. the rate of usage of stock may not be constant, during busy times stock levels will fall a lot quicker. the benefit of a stock control diagram is that it gives the firm a clear picture of how stock levels have changed and to identify the reasons for these changes

lean production:
JIT is a key part of lean production. this is a philosophy that attempts to eliminate all forms of waste from the production process. by reducing waste, the business can improve efficiency and lower its unit costs. this provides it with a competitive advantage:


  • using the ideas of staff through kaizen groups who meet regularly to suggest ideas for improving productivity and quality
  • maintaining high levels of quality throughout the production process
  • quicker speed of production and development of new products