Complementing the textbook, Environmental Assessment of Products (series), this workbook introduces practical execution of LCA. The case-studies are constructed to optimise the learning process. They demonstrate the methods and common mistakes experienced in real-life assessments. The reader is guided in a critical review of the studies, increasing his understanding of good and bad practice in LCA. The new knowledge can then be applied in the reader's own LCA study, using the comprehensive data supplied.
The workbook presents two fictional life cycle assessment reports about baby diapers. Both reports use the same data, but interpret those data differently, leading to diverging results. This setup gives readers a way to examine how methodological choices and assumptions can affect an LCA, rather than treating an assessment as a calculation with only one possible interpretation.
The exercise is designed for students to analyse the two studies and discover the implications of the choices made in each one. The accompanying data support practical work: readers can review the studies, compare their reasoning and apply what they learn to an LCA of their own. The workbook therefore connects methodological discussion with hands-on assessment and critical review.
The original exercise book dates from 1994. Its author, Bo Weidema, notes that it is outdated in several respects, including impact assessment methods and the state of data collection and interpretation. He also argues that the underlying teaching approach remains useful: learners can improve their understanding by working through an assessment themselves. The book is shared as a resource for discussion within the LCA community and as a possible starting point for an updated version using modern LCA techniques.
Readers can use the cases to ask which assumptions differ, how those differences shape the interpretation of the shared data, and whether the conclusions follow from the choices made. They can also consider what evidence would be needed to justify an assumption in a real study. These questions make the workbook useful for practising careful review and for discussing how LCA results should be explained to decision-makers.
The cases are fictional teaching exercises, not current product benchmarks. Because the book reflects the methods and data practices of its time, its numerical examples should not be treated as up-to-date diaper footprints. Its value is in the opportunity to examine reasoning and methodological choices. Anyone adapting the exercise for current work should use appropriate contemporary data and impact assessment methods.
