Processes

A process illustrates the production or a modification of a substance or product. It comprises flows as inputs and outputs. There are unit processes and LCI systems, i.e. aggregated processes. If you open a process by double clicking on it, it looks like this:

At the bottom of the editor, you find several tabs with different functions. For example, if you go to the tab „Inputs/Outputs”, you can add or delete input and output flows with the plus and the minus symbol which are located at the top right. As advanced features you can label input flows as avoided products, add allocation, define parameters, or assign probability distributions to the different flows (see Advanced functions).

Creating a new process

The input and output list of all flows for a process is probably the most important part of the process. In order to create this list, the flows first need to exist, and if they don’t, need to be created as flows (see in the Flows sheet). In Life Cycle Assessments, each process has one flow as quantitative reference. All other flows are scaled according to this quantitative reference. You „declare” one of the input or output flows in the tab „General information” of the process, see below.

Let’s look at one example: We create a process that produces potatoes.
1. Open the wizard and create a flow with the name „Potato, at field”, the property „Mass”, and the type „Product flow” (see flows). Save the flow.
2. Open the wizard and build a process with the name „Potato” and select the flow „Potato, at field” as reference flow. Click on „Finish”.

The process editor of the new process will be opened. In the first tab you can add general information about the process. Under the tab „Inputs/Outputs” add input and output flows you need for your process. In our case we add carbon dioxide, fertilizers, water, land occupation, and potato plants. An output flow is already given – it is our quantitative reference, the others are ammonia, potato leaves, and nitrogen.

You can change the mass/amount of the flows as follows: If you mark a flow and change the factor in the field „properties” under the process editor and press Return.

If you have a multi-output process you most likely need to apply allocation or system expansion (see advanced functions).