Environment industries archive
Key departmental publications, e.g. annual reports, budget papers and program guidelines are available in our online archive.
Much of the material listed on these archived web pages has been superseded, or served a particular purpose at a particular time. It may contain references to activities or policies that have no current application. Many archived documents may link to web pages that have moved or no longer exist, or may refer to other documents that are no longer available.
|Objective of this Session||To learn a methodology for collecting data on annual usage and wastage, and to identify business processes.|
|The following topics will be covered in this session|
|Process Characterisation - Flow Diagrams|
|Process Characterisation - Input/output diagrams|
Flow diagrams are simple graphics that show the sequence of steps (activities) which together make up a full process.
Cleaner production assessment requires an analysis of each business process and unit process. The tools described in this session will help in identifying all the inputs and outputs to each process, including all waste streams.
Identify the unit processes that make up each process, then construct the flow diagram. Each unit process, as defined earlier, should comprise an individual step or activity within the whole process.
Keep the flow diagram relatively simple in the preliminary assessment - it can be expanded in the detailed study if required.
As an example of a flow diagram, the process of laundering clothes can be divided into the following six unit processes and shown in the following flow diagram (Figure 12.1):
|Collect and sort clothing|
|Load washing machine|
|Operate washing machine|
|Remove washed clothing|
|Shut down washing machine|
Figure 12.1: Flow diagram for laundering clothing in a washing machine
Business operations typically include ancillary processes that are associated with the core process. Ancillary processes typically fall into one of four categories:
In constructing input/output diagrams, always include ancillary unit processes.
Consider the flow diagram below (Figure 12.2) for making and distributing bread in a wholesale bakery. This flow diagram includes several ancillary unit processes.
|Dispose of Returns|
Figure 12.2: Flow diagram for a wholesale bakery
Objective: to practice constructing a flow diagram.
Using the above flow diagram as a model, construct a flow diagram for the making of hamburgers at a local fast food shop. Include ancillary unit processes.
An input/output diagram shows, for each unit process, what materials and energy go into the process and what comes out of it.
Now that all unit processes have been identified, the next step is to identify the main material and energy inputs and outputs from each unit process. This will lead into the next stage (usage maps) when a breakdown of the quantities and costs of each business input and waste output is developed.
In the project, input data is collected only on major raw materials, energy and water; output data is collected only on product and waste. (This restriction is used to keep the cleaner production assessment to a manageable size). It is important to note that in a full cleaner production assessment, this restriction is not imposed.
Following on with the earlier example of making and distributing bread in a wholesale bakery, inputs and outputs can be assigned to each unit process of the flow diagram to obtain an input/output diagram (shown in Figure 12.4). Note that only product and waste outputs are shown.
|flour, yeast, fats, oils, electricity (refrigeration)||®||Storage||®||useable ingredients, spoiled ingredients|
|flour, yeast, fats, oils, water, electricity (or gas)||®||Mixing||®||raw dough, waste dough, cleaning wastes, packaging wastes|
|raw dough||®||Proving||®||risen dough, waste dough, cleaning wastes|
|risen dough, electricity (or gas)||®||Baking||®||bread, heat, emissions, waste bread fragments|
|bread, plastic wraps, wire baskets, electricity||®||Packaging||®||packaged bread, packaging wastes|
|packaged bread, vehicle fuel||®||Distribution||®||bread in retail shops, damaged bread, vehicle exhaust emissions|
|unsold, damaged bread returned from retail shops||®||Dispose of Returns||®||waste bread (sent to stock feed producers)|
|pesticides||®||Pest Control||®||pesticide residues, dead pests|
|cleaning consumables, water, electricity (heat water)||®||General Cleaning||®||cleaning wastes, dirty water|
Figure 12.4: Input/output diagrams for a wholesale bakery
When identifying unit process inputs and outputs, try to talk with employees working with those processes. However, while these employees will give good information, some inputs and waste outputs may be overlooked because they are too familiar with the process. Talk to other employees and, perhaps more importantly, walk around the business premises and take a good look.
For every input, there must be a corresponding output. Make sure that there is an output for each input to a unit process. If there is a weight change in a raw material or product, account for the difference and make sure it is included in the input/output diagram. Remember all wash water, atmospheric emissions, dust and any pollution.
Balancing inputs and outputs is a useful method of tracking down waste outputs that may otherwise be overlooked.
Include any scrap (raw material or product) that is regularly or spasmodically produced in the process.
Note that quantities and costs are not required in the input/output diagram at this stage.
Objective: to practice developing input/output diagrams for small business processes.
Construct an input/output diagram for the making of hamburgers at a local fast food shop. (Use the flow diagram developed earlier). Pay particular attention to identifying wastes such as unused food, packaging, washwater and gaseous emissions.