Page 53 - Materials Chemistry, Second Edition

48 3. Life cycle thinking tools: Life cycle assessment, life cycle costing and social life cycle assessment

Contrary to LCA methodology, which is standardized by two ISO standards, LCC is not
structured by a specific international standard. The standard ISO 15686-5:2008 provides the
instructions and the guidelines for the application of this methodology in the building sector,
thus it cannot be applied to other contexts. However, some authors propose a methodology
comprised of 10 steps to conduct an LCC study. All the 10 phases are required; they can be
implemented in sequence, but also out of sequence, or sometimes simultaneously (Dhillon,
2010). The 10 steps are as follows (Dhillon, 2010):
1. Determine the purpose of the LCC analysis.
2. Define and scope the system/support system.
3. Select the appropriate estimating methodology/LCC model.
4. Gather data and make the appropriate inputs to the methodology/model.
5. Perform sanity checks of input and outputs.
6. Perform sensitivity analysis and risk assessment.
7. Formulate the results of the LCC analysis.
8. Document the LCC analysis.
9. Present the LCC analysis.
10. Update the LCC analysis/baseline.
The steps proposed by Greene and Shaw (1990) can be grouped in four phases, in line with
LCA methodology, as reported in Fig. 3.4.

3.2.1 Goal and scope definition

The identification of the purpose for conducting an LCC study is the first necessary step. In
some cases, the purpose may be obvious or predetermined, as in a source selection LCC anal-
ysis. Nevertheless, in other cases, when the purpose is not sufficiently clear, considerable ef-
forts can be made before understanding the direction of the study. In this phase, the required
issues to conduct the study are defined, including the criteria to be used for selection of al-
ternatives. The goal of an LCC analysis may be a comparative analysis of a new system versus
an existing system, or provisioning purposes (Greene and Shaw, 1990). The scope definition
includes the system units to be included in the study, the definition of the subject of the study,
the definition of assumptions, and the identification of limitations.
Usually, the system and subsystems are not completely defined until the final design, and
the scope need to be revised. In the beginning of the study, the system definition and the scope
may be vague. If the system under analysis is replacing or is similar to an existing system, it is
important to include similarities and differences. This step is fundamental to ensuring a
credible LCC analysis (Greene and Shaw, 1990). The selection of an appropriate LCC model
depends on several factors, such as the type of system/support system/subsystem to be
analyzed, the system units included in the life cycle and the type of analysis to be conducted,
as defined in the first step.
The amount of data available to conduct an analysis is determined by the phase of devel-
opment of the product or process under analysis. Only limited data may be available during
the research and development phase, and so for instance parametric cost estimating models
can be appropriate. If the product is under production, or a process is operative, there may be