Waste Minimisation in Plastics Processing - Part 5 Waste Minimisation Tools

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Waste minimisation tools

The key tools in waste minimisation are the ‘waste tracking model’ and the ‘cause and effect diagram’. These help to find both ‘fast starts’ and to develop a systematic approach for long-term savings.

1 - The waste tracking model

To manage waste effectively and to pinpoint where savings can be made, all the different wastes produced by a company (and the stage at which they are produced) needs to be identified. The tool used for this is the ‘waste tracking model’. A general ‘waste tracking model’ for plastics processing is shown. Each process step both adds value and incurs a cost from the labour, materials and utilities used in the process step.

Tip - The true cost of waste includes the cost of wasted resources and rejects at each stage in the process. The cost of rejects includes the value added to the material by the time it is rejected and this increases through the process.

General waste tracking model for plastics processing

Waste tracking to identify costs

Consider your production operation as a series of processes. Each process has its own inputs, outputs and waste. Using the example, you can make a waste tracking model for your complete process. Once you have this global view of the process, create an ‘opportunity sheet’ for each step of the process. This sheet places amounts and costs on the wastes for each step. Add up the total costs to give the overall cost of waste to your business.

Tip - If the information you need is not available, either make a ‘best’ guess or carry out some simple measurements and decide whether improved information collection is justified.

You should now have a good picture of the ‘cost of waste’ to the business. Combine the details from the waste tracking model to see if there are discrepancies in overall values, i.e. between identified and total actual water use, and raw material and energy consumption. 

Tip - Dig deeper if there are major discrepancies. They may be a major cost and a major savings opportunity!

2 - The ‘cause and effect’ diagram

‘Cause and effect’ diagrams are a standard tool for quality improvement and will be familiar to many people. They are used to identify opportunities for eliminating waste in each process step and are useful when you need to identify possible causes of a problem in a structured manner. For each effect there are likely to be several causes.
In manufacturing, the key causes are:

• people
• methods
• materials
• machinery
• measures

Remember to look for ways to cure the cause (or causes) of the problem and not just the symptoms.

The 'cause and effect diagram

Tip - Ask the people who work on the process to suggest reasons (without blame) for the problem

Tip - List their suggestions against each cause (they know the process better than you!

Tip - Involve everyone in the development of solutions

Tip - Implement no-cost measures as soon as possible

The future

This short series has only touched the surface of waste minimisation in plastics processing. The implementation of these powerful techniques can save your company real money as well as making you more environmentally friendly. For further free details, information and assistance contact the Helpline.

The "Waste Minimisation" series is designed to give plastics processors an insight into how to minimise wasting  valuable resources. The series is being published in British Plastics and Rubber on a monthly basis and published here after the BP&R publication. The series is:

Part 1: The Business Reasons

Part 2: A Waste Walk Around and Action Plan

Part 3: Assessing Performance

Part 4: Improving Performance

Part 5: Waste Minimisation Tools (This section)

 

Download the complete series as an Adobe Acrobat file.

 

Last edited: 29/03/04

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