What is CMLCA?

CMLCA in a nutshell

CMLCA is a software tool that supports the calculation of:

CMLCA is intended to support the technical steps of the tools described. It does not support the procedural aspects, like peer review, involvement of stakeholders, quality assurance and usefulness of the analysis for the decision at stake. The program assumes that the user is aware of the basic principles of LCA, IOA, etc.

CMLCA is just one of the many software tools that is available for the stated purposes. However, its philosophy is probably somewhat different. CMLCA does not provide a flexible user interface. Exchange of data with other programs is less extensive than with some other programs. There is only a small choice in graphical output, and the graphs are not 'fancy': no 3-D bars with shadow, just straight bar charts. There is no helpdesk. It may contain programming errors.

On the other hand, it is developed with the principles of LCA, IOA, etc. in mind, so that it is quite accurate and up-to-date as to methodological details. It is, for example, fully based on matrix algebra, although the user may be unaware of that whilst using the program. This implies that process trees with a recursive flow structures (steel production needing coal and coal production needing steel), provide no computational problems and are exactly solved. Moreover, the program is very flexible in dealing with allocation of multiple processes. In contrast with some other programs, such processes need not be allocated prior to their entry in the database, and the allocation method (substitution, partitioning, or no allocation at all) may be defined for each individual unit process. The program also supports fully hybrid inventories, consisting of process-based and IO-based data. It is rich in its analytical possibilities.

The program will continue to develop, in a progressive way such that all present features will remain available, and that data saved with the present version may be retrieved in future versions. CML, the Institute of Environmental Sciences at Leiden University, has ever since the conception of LCA played a prominent role in developing LCA, and it is still at the forefront of activity, both in its methodological advances, and in its standardization and progress towards maturity. CML has also been very active in EIOA and hybrid analysis the last few years. CMLCA will follow these developments, and sometimes it will even lead these.

CMLCA is scientific software, in two senses:

CMLCA, finally, is freely downloadable and need not be installed.

Why use CMLCA?

Seven reasons for using CMLCA

  1. CMLCA is for free. Most software for LCA will cost you several thousand of euros.
  2. CMLCA is extremely flexible. Most software for LCA has a pre-cooked allocation, impact assessment, etc. In CMLCA, you can control (almost) everything.
  3. CMLCA is perfect for use in class room. Most software for LCA is designed for use by consultants. That means that ease of use has been more important than correctness and transparency.
  4. CMLCA is perfect for use by scientists. It comprises the most extensive set of options for doing life cycle interpretation, and it includes extensive options for addressing environmental impacts in connection to EIOA.
  5. CMLCA is extremely advanced in including IO-based and hybrid LCA, LCC and eco-efficiency analysis.
  6. CMLCA is compatible with the framework and terminology of ISO 14040.
  7. CMLCA does not require an administrator for installation, and can be transferred over the internet, for instance for download by your students.

Seven reasons for not using CMLCA

  1. CMLCA has no helpdesk.
  2. CMLCA contains no data. You still have to buy or download these.
  3. CMLCA contains no impact assessment data. You still have to incorporate GWPs and related characterisation factors.
  4. CMLCA is not so good for consultants. A consultant wants an easy and quick answer, and doesn't like having to choose from too many options.
  5. CMLCA has no graphical interface for constructing flow diagrams.
  6. CMLCA is only available in English.
  7. CMLCA is only available for Windows.

CMLCA: to use or not to use?

The choice is yours: seven arguments pro and seven against. You can at least give it a try.

Scientific software?

So, why would CMLCA claim to be scientific software? Of course this is subjective and debatable, but there are good arguments:

Concerning this last point, important aspects has been published in the following books:

and in the following journal articles: