Please consider using an economic input-output model. Alternative (other-than-process-based) methods of calculating net product impact can provide quick, cost effective, and yet comprehensive life-cycle assessments. A free economic input-output LCA is available via the Green Design Institute at Carnegie Mellon.
LCA can currently be performed 2 ways: 1) Process-based or 2) economic input-output based.
LCA [O]ne needs to
identify the inputs, such as pulp, water, and dyes to make the paper,
the trees and machinery to make the pulp, and the forestry practices
to grow and harvest the trees. Similarly, one needs to include inputs
and outputs for packaging the cup for shipment to the store, the trip
to the store to purchase the cups, and that result from throwing the
cup in the trash and eventually being landfilled or incinerated. Even
for a very simple product, this process-based LCA method can quickly
spiral into an overwhelming number of inputs and outputs to include.
Now, imagine doing this same process-based LCA for a product such as
an automobile that has over 20,000 individual parts, or a process such
as electricity generation.
Advantages: detailed, process specific; allows for product specific comparison
Disadvantages: time-intensive; system boundary is subjective; proprietary
An internet search brings several reputable vendors, but as mentioned, these processes are usually very thorough and rather expensive.
Economic Input-Output: Inputs to the automobile manufacturing industry sector include the
outputs from the industry sectors that produce sheet metal, plate
glass windshields, tires, carpeting, as well as computers (for
designing the cars), electricity (to operate the facilities), etc. In
turn, the sheet metal, plate glass windshield tire, etc. industry
sectors require inputs for their operations that are outputs of other
sectors, and so on. Each of these requirements for goods or services
between industry sectors is identified in an EIO model.
Advantages: results are economy-wide, comprehensive assessments; allows for systems-level comparisons; uses public data; reproducible; generally quicker
Disadvantages: product assessments contain aggregate data; process assessments are difficult; must link monetary values with physical units
It's important to note that many of the data sets here are US, but the site also provides links to Canadian, German, and French data.
FYI: Economic Input-Output LCA models are founded on Wassily Leontief's Nobel Prize winning theory.