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Business Sustainability: A cleaner production approach to small business management

Student Manual

Environment Australia
October 2000
ISBN 0642547149

Business Sustainability: Session 12 - Preliminary Assessment - Part 3

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

Process Characterisation - Flow 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.

Constructing Flow Diagrams

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.

Example of Flow Diagram

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
Hang washing

Figure 12.1: Flow diagram for laundering clothing in a washing machine

Ancillary Unit Processes

Business operations typically include ancillary processes that are associated with the core process. Ancillary processes typically fall into one of four categories:

Include Ancillary Unit Processes

In constructing input/output diagrams, always include ancillary unit processes.

Another Example

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
Pest Control
General Cleaning

Figure 12.2: Flow diagram for a wholesale bakery

Class Activity

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.

Process Characterisation- Input/output Diagrams


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.

Important Note

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.


Inputs   Unit Processes   Outputs
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

Identifying Inputs and Outputs

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.

Balance Inputs and Outputs

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.

Not Quantitative

Note that quantities and costs are not required in the input/output diagram at this stage.

Class Activity

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.