How to perform an LCA 

An overall piece of advice is that you should spend enough time in the goal and scope definition and the interpretation phases, and avoid overspending time in the data inventory phase. Additionally, try to involve the result user and other relevant stakeholders as actively as possible in the LCA process.

Goal and scope definition
Proper definition of goal and scope is important. Realize that it is a resource demanding task to conduct a full LCA. In practice it is not always necessary to conduct full LCAs. Sometimes you only need rough results. A limited LCA could be relevant if the goal is to compare two construction materials in a specific phase of a product development project. On the other hand, a comprehensive LCA could be relevant if the result will be communicated to an external audience. 

The intended use of the results is important to consider in the goal and scope definition phase. Common LCA applications in ABB are product development and marketing. In product development projects LCA is used to identify significant environmental aspects for defining sustainability objectives according to the ABB Gate model. In marketing, LCA results are used to communicate environmental benefits to customers through LCA based EPDs.

Inventory analysis  
The inventory phase is the most time consuming step of an LCA. The needed inventory data are often difficult to retrieve since you need to involve various actors in the supply chain, mostly outside your own company’s control. The level of ambition to collect data "for every screw" could be a little bit too high among LCA practitioners who are conducting their first LCAs. The advice is to be realistic already in your goal and scope definition regarding what inventory data that should be collected. 

Even if limiting system boundaries is difficult you should try to make a first estimation of what materials, components and processes components to be included in the LCA as early as possible in your study. You could make a first telephone contact with potential data suppliers to check if it is expected that suppliers could provide you with input data or not. 

The inventory data quality is difficult to handle in practice. Unfortunately there are no commonly accepted numerical criteria available to easily assess the data quality. The data quality requirements depend on the situation and application where the data are used, why there are no “good” or no “bad” data in absolute terms. Imagine two products containing polycarbonate. The first product contains 50% polycarbonate and the second 3% polycarbonate. It is obvious that a crude inventory data set for polycarbonate might be of enough quality for the second product but probably not for the first. A practical advice to overcome this is to conduct a first screening LCA to identify critical materials and processes and then spend most time on retrieving inventory work for the critical data sets.

Impact assessment  
Selection of impact assessment method must be based on the studied system since this varies a lot between different product systems. A common impact assessment method used in ABB is GWP, Global Warming Potential, since ABB’s products are converting or transmitting energy in one way or another.

You can evaluate the results on different levels, for example:

• Life cycle inventory analysis results in summarized inventory values in mass or energy units, for example "The studied product releases 40.000 kg CO₂ during its life cycle". This is an objective way to present the results. It is however not easy to interpret the results without being an expert in ecology.  
• Characterization results in different environmental impact categories. GWP, Global Warming Potential, and AP, Acidification Potential exemplifies two such categories. This way of presenting the results is common and it is used in EPDs, Environmental Product Declarations.  
• Weighting shows the results aggregated into one single number for each assessed product. This is an optional part of an LCA and should always be used with care. 

Interpretation of the results 
The last concluding part of an LCA study is to interpret the result in relation to the intended audience. To do this you need to understand the intended application. Since LCA is a complex tool there is a risk of confusing the users with a very large amount of figures, tables and diagrams, that may all be relevant but difficult to understand. A piece of advice is therefore to spend enough time in structuring the report from a user perspective.

Business value 
It is good business to understand the environmental impacts of your product system since cost efficient improvement actions could then be taken and business relevant information could be selected for use in market communication.