The function of the product system, or in the case of comparative studies, the systems;. Identification of the significant issues based on the results of the LCI and LCIA phases of LCA;. SLCA is best applied during preliminary evaluation of the environmental impacts of a product system (Lee, Kim, Kwon, & Hur, 2003).
The advantage of the MECO framework is that individual sources of environmental impacts do not overlap in the assessment of all relevant environmental issues. Elimination problem: Allows the elimination of elements as a branch of the ranking problem (Bana E Costa, 1996). For example, the second-level criteria are compared in a pairwise fashion with the scope of the decision problem.
The results, based on the global flows, provide a ranking of actions as well as a graphical representation of the decision problem (Ishizaka & Nemery, 2013). MCDA is rarely seen for use in the target and scope phase of the LCA process. However, a limitation of this work was due to the extensive use of experts in the evaluation of the systems.
In addition, MCDA can be integrated into the goal and scope phase of the LCA process to allow the development of the system and scope to be evaluated. SLCA can be applied instead of the Full LCA to allow for evaluation during the planning stages for environmental decision making. The purpose of the LCA is to evaluate and compare the environmental impacts of the potential end-of-life management of MSW to evaluate environmental impacts and to inform the zero waste plan for Metro Nashville.
The LCA will inform Metro Nashville of the environmental and economic impacts of potential MSW end-of-life technologies in order to select a MSW system with the least environmental impact. The LCIA results for the three scenarios using MSW-DST are shown below. Material movement results for each are optimized for energy, cost and CO2.
The acidity of the environment can be due to chemical reactions or biological activity (Bare, 2012). The results collected provide a ranking of environmental impacts for each stage of the life cycle, with higher indicating lower impact. SLCA allows simplification of system boundaries and inputs, considering only five environmental impacts and five life cycle phases.
In Chapter V, DecisionTogether© will be applied to the evaluation of the future end-of-life systems for municipal solid waste (MSW) management systems by stakeholders.
Define the problem
Develop the hierarchy model
Construct a pairwise comparison matrix
Perform judgment for pairwise comparison
9 Extreme importance Evidence favoring one criterion/alternative over another is the highest possible level of confirmation. The priority vector for each element is calculated by summing each row of the matrix and dividing by the number of elements. The consistency of the answering process is checked mathematically to ensure that the participant consistently completes the pairing process.
The judgments provided may not reflect the views and opinions of the stakeholders on the envisaged trigger. Consistency is checked by calculating the Consistency Index (CI) and the Consistency Ratio (CR). Inconsistency can occur during pairwise comparison, where individual judgments can be influenced by a lack of rationality and violate the consistency condition of the matrix.
Power and geometric scales expand the values of the matrix elements from 9 to 81 and 256, respectively. The geometric mean uses the judgment of the stakeholder to calculate the total score to provide the overall judgment of the stakeholder, where the inputs of all stakeholders are considered equal. Individual identities are lost with each level of aggregation, and the synthesis of hierarchy creates group priorities.
Often, evaluation is not about individual priorities because each individual participates and makes judgments as part of the evaluation process for each cluster in the hierarchy (Forman & Peniwati, 1998). Steps must be taken to aggregate the resulting information to evaluate the preference of the entire stakeholder group as well as subgroups. In this assessment, the relative importance of stakeholders may be assumed to be equally important or otherwise incorporated into the aggregation process (Forman & Peniwati, 1998).
The stakeholder group then merely aggregates the member's final scores to arrive at a group vision of the alternatives. This model creates a single composite stakeholder whose criterion weights are a compromise of the weights of all group members and a composite of the pairwise ratings. AIJ occurs at the judgment level when assessing the hierarchy and evaluating the relative importance of the criteria.
LCA SLCA
These experts can be part of the stakeholder group holder used for the AHP evaluation. The AHP is used to develop local priorities of stakeholders as individuals and as a group. For each particular elicitation, the developer must determine the purpose of the specific elicitation session.
The SLCA and AHP processes begin with the definition of the objective and scope, which translates into the objective of the evaluation. The study includes residents due to their important role in waste sorting and implementation of the MSW plan at the residential level. In this case, only environmental impacts were considered in the AHP evaluation, with stakeholders provided with the results of the full LCA data to assist their AHP evaluation.
The developed criteria and characteristics are based on the goal and purpose of the decision-making process. The characteristics of the environmental criterion included raw materials, reduction of landfilled biodegradable MSW, emissions to the environment and hygienic conditions affecting human health. I think your answers will vary greatly depending on the user's knowledge of the waste management technologies available.
The goal of the solicitation is to determine which residential end-use MSW management system to implement for Metro Nashville. At the end of the presentation, participants were asked to provide their contact information if they wished to participate in the elicitation. Interview stakeholders to determine if their priorities align with their understanding of the criteria, attributes, and scenarios.
The general public stakeholders are those who dispose of the MSW, but tend to have little interaction with the steps from transport to end-of-life management. Stakeholder priority scores were combined using the geometric mean to develop group priorities for the three identified groups as well as for the entire stakeholder group. In reviewing the individual priorities, there was a high degree of variability, which placed technical feasibility as the highest priority criterion.
Attributes were evaluated in a pairwise comparison with respect to the criterion and the purpose of the evaluation. The evaluation of the attributes aims to provide information about the aspects of the criteria that are most or least important to the stakeholders.
