Stock Control (Edexcel A Level Business)

Revision Note

Lisa Eades

Written by: Lisa Eades

Reviewed by: Steve Vorster

Interpretation of Stock Control Diagrams

  • A stock control diagram illustrates the flow of stock (inventory) into and out of a business over time

Stock level graph over 10 weeks showing stock units held. Maximum 1600, reorder 800, minimum 400 units, lead time and buffer stock indicated.

An example of a stock control diagram 

Diagram Analysis

  • The maximum stock level is the maximum amount of stock a business is able to hold in normal circumstances (1600)

  • The reorder level is the level at which a business places a new order with its supplier (800)

  • The minimum stock level is also known as the buffer stock level and is the lowest level to which a business is willing to allow stock levels to fall (400)

  • The lead time is the length of time from the point of stock being ordered from the supplier to it being delivered (1 week)

  • The stock level line shows how stock levels change over the given time period

    • As stock is used up a downwards slope is plotted

    • When an order is delivered by a supplier the stock level line shoots upwards

Worked Example

The diagram below shows stock movements of kitchen shelving units sold by TamFix Ltd.

Graph showing stock levels over four weeks, with stock dropping from 1000 to 200, then replenishing at reorder level of 500 each week.

Identify the following points:

  1. the minimum stock level

  2. the re-order level

  3. the re-order quantity

  4. the lead time for kitchen shelving units    (4)

Step 1 - Identify the minimum stock level

The minimum stock level is identified by the bottom-most dotted line - in this case it shows that the minimum stock level is 200 units   (1 mark)

Step 2 - Identify the reorder level

The reorder level is clearly identified on the diagram - in this case it shows that the reorder level is 500 units (1 mark)

Step 3 - Identify the reorder quantity

The reorder quantity is the difference between the maximum stock level (shown by the topmost dotted line) and the    minimum stock level

1000 units - 200 units = 800 units

The reorder quantity is therefore 800 units   (1 mark)

Step 4 - Identify the lead time for kitchen shelving units

The lead time is the difference in time between an order for stock being placed and its delivery. In this case, assuming a five-day working week, the lead time for shelving units is two days (1 mark)

Buffer Stocks

  • Buffer stock is a quantity of goods/raw materials kept in case of stock shortages

    • This can provide a  competitive edge  over rivals unable to meet demand

    • This approach is commonly called ‘just in case’ stock control

  • The decision to keep buffer stocks is one that businesses have to weigh up very carefully

    • The decision will be influenced by the nature of the business and the product/service it provides

The Advantages & Disadvantages of Holding Buffer Stocks

Advantages

Disadvantages

  • Stability in supply
    Buffer stocks ensure a stable supply of goods which is able to respond to unexpected customer demand

  • Price stabilisation
    Buffer stocks can help prevent extreme price fluctuations as it helps the market to avoid shortages, which would result in rapid price increases

  • Raw materials security
    Businesses that are dependent on particular raw materials avoid disruption to their supply

  • Competitive advantage
    By having a reliable supply of goods, businesses can gain a reputation for always being able to meet the needs of their customers

  • Cost
    Holding buffer stocks can be expensive, as it requires storage facilities and inventory management systems

  • Risk of obsolescence
    Buffer stocks can become obsolete if the demand for a particular product or input declines

  • Opportunity cost
    Holding buffer stocks ties up capital that could be invested in other areas of the business

Implications of Poor Stock Control

2-4-3-the-implications-of-poor-stock-control

Implications of poor stock control

  • Problems may arise from holding too much stock

    • Storage costs (e.g. warehouse rental, security costs) will be higher than necessary 

    • The risk of spoilage and stock shrinkage will be increased, leading to increased costs

  • Similarly, holding too little stock is risky

    • A business may run out of stock, resulting in production stoppages and higher unit costs related to underused capacity

    • A sudden increase in demand may not be capable of being met and this leads to a loss of potential sales revenue

Just in time (JIT) Stock Management

  • Just in Time (JIT) stock management is a process in which raw materials are not stored onsite

    • Stock is ordered as required, and delivered by suppliers 'just in time' for production

  • Careful coordination is needed to ensure that raw materials and components are delivered by suppliers at the moment that they are to be used

The Advantages and Disadvantages of Just-in-Time Stock Management

Advantages

Disadvantages

  • Stockholding costs, including storage costs, are minimised

  • Close working relationships are developed with a small number of trusted suppliers

  • Cash flow is improved as money is not tied up in stocks

  • Unused storage space is available for productive use

  • Teamwork is encouraged so employee motivation is likely to be improved

  • Bulk buying economies of scale  are not generally possible

  • The ability to respond to unexpected increases in demand is reduced

  • Administrative costs related to frequent ordering are increased

  • Unreliable suppliers (e.g. late or poor quality deliveries) can quickly halt production

  • Significant changes to organisational structure  and production controls are required

Waste Minimisation

  • Waste in a business can occur for a number of reasons

    • Stock becomes obsolete unless used by a particular date

    • Perishable stock (food and medicines) that is not used before they deteriorate will need to be thrown away

    • Stock may be damaged as a result of poor storage conditions and may not be suitable for use in the production process

  • Allowing waste to go unchecked will increase the unit costs of production and reduce both efficiency and productivity

  • Businesses may take a range of steps to minimise waste

2-4-3-waste-minimisation

Ways to minimise waste

  • The minimisation of waste will depend upon the nature of the product

    • For perishable items, refrigeration and careful stock rotation can reduce waste

  • Staff training and computer inventory management systems may also reduce waste as fewer errors are likely to be made

  • Effective sales forecasting can help to reduce the amount of wasted stock

Competitive Advantage from Lean Production

  • Lean production involves the minimisation of the resources used in production

    • Less time is required as the production process is organised in the most efficient way

    • Fewer materials are used as there is a focus on waste reduction

    • Less labour is used as lean production is typically capital intensive

    • The space required for production is reduced as a result of just in time stock management

    • A small number of trusted suppliers work closely with the business

  • The use of lean production is likely to lead to a competitive advantage 

    • Lower  unit costs  are achieved due to minimal wastage, so prices may be lower than those offered by competitors

    • Better quality of output is likely as a result of supplier reliability and carefully managed production processes

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Lisa Eades

Author: Lisa Eades

Expertise: Business Content Creator

Lisa has taught A Level, GCSE, BTEC and IBDP Business for over 20 years and is a senior Examiner for Edexcel. Lisa has been a successful Head of Department in Kent and has offered private Business tuition to students across the UK. Lisa loves to create imaginative and accessible resources which engage learners and build their passion for the subject.

Steve Vorster

Author: Steve Vorster

Expertise: Economics & Business Subject Lead

Steve has taught A Level, GCSE, IGCSE Business and Economics - as well as IBDP Economics and Business Management. He is an IBDP Examiner and IGCSE textbook author. His students regularly achieve 90-100% in their final exams. Steve has been the Assistant Head of Sixth Form for a school in Devon, and Head of Economics at the world's largest International school in Singapore. He loves to create resources which speed up student learning and are easily accessible by all.