Real-time multi-user LCA: live modelling as a team

Traditional desktop LCA tools (SimaPro, GaBi, openLCA) are single-user file-based — one person locks the model, edits, saves and closes; someone else opens it next. In complex projects this lock-based flow adds hours of waiting. clca offers a browser-based real-time multi-user editor: team members work on the same LCA simultaneously, others' changes appear on your screen within a second.

How live sync works

clca uses a CRDT (conflict-free replicated data type)-based data structure. Each user action (adding an inventory item, updating an amount, mapping to ecoinvent) is processed as an operation; conflicts resolve mathematically. If two users edit the same row in parallel, last-write-wins does not apply — field-level merging happens. Each user's cursor and selection appear on others' screens with a coloured badge.

Live mass-flow balance

In an LCA model, input and output mass must balance — 1 kg of product needs 1.2 kg raw + 0.18 kg waste + 0.02 kg loss = 1.4 kg in, 1.0 kg product + 0.4 kg waste = 1.4 kg out. Traditional tools check this only after "Calculate"; errors force a model reopen. clca validates the balance live as you type; an unbalanced row turns red with a "+0.05 kg short" annotation.

LCA copy: variant products in minutes

You modelled one product. Now you need variants in different size, thickness, strength, colour. clca's "LCA copy" clones the existing model — all inventory, ecoinvent mapping, LCIA method, DQR scores carry over — and you only update the differing parameter. Five thickness variants of an insulation product cost about 20% of the first model's effort.

Custom activity creation: extend ecoinvent with local data

ecoinvent v3.12 is the world's broadest LCI database, but it does not contain your local supplier data. clca's custom activity creation starts from an ecoinvent activity and lets you update at the parameter level. Example: take ecoinvent's "PE granulate production (RoW)" and localise it to reflect your supplier's renewable-electricity share. The user-defined set is shared within your organisation and the source is logged.

Typical use cases

• Manufacturer + consultant + verifier: communicate in the same file, no emails
• During the EPD program, verifier comments are pinned at sentence level
• In-house LCA team: 3 people work a 30-product portfolio in parallel
• Academic thesis group: supervisor leaves live feedback on the student's model
• Teaching: the lecturer demos a live LCA model to the class