Integration of CO2e-emissions in Discrete-Event Simulation for Decision Support

Sammanfattning

Purpose – Current literature indicates the potential of incorporating environmental sustainability metrics such as greenhouse-gas emissions in simulation modelling as support for decision-making. Despite this, it has not been established as practice in industry, and literature is rather limited regarding considerations connected to the development of, and use of such models. Therefore, the purpose of this study is to develop and test an approach for the integration of CO2-equivalents (CO2e) as a common unit of measurement for emissions in discrete-event simulation (DES) models, and to investigate the potential use-cases, benefits, and challenges of developing and using such simulation models in decision-making contexts within the manufacturing-domain. Method – This thesis is a single-case study where the Design Research Methodology-framework served as the methodological foundation. Within the case study, a systematic literature review was conducted to form a state of the art, which served as the literary basis for this thesis. A state of practice was also produced through interviews and observations. A synthesis of the two resulted in requirements and goals for the development process, constituting the approach which involved simulation modelling and a document study. Finally, an initial evaluation of the developed model as a decision-support system (DSS) was conducted through semi-structured interviews with a variety of industry professionals within the case-company. The empirical data in this thesis were primarily analysed using content- and thematic analyses. Findings – The findings of this thesis indicate that incorporating CO2e in DES-modelling with high accuracy is possible, but that a successful incorporation requires careful consideration before developing the model, and during the use of the model as decision-support. From a technical perspective, considerations related to data availability, relevance, reputation, and timeliness, along with software capabilities are most apparent. From an organisational perspective, considerations such as key performance indicators and goals, simulation- and data analysis competence, trust in simulation modelling and their outputs, and workplace routines, checklists, and standardisation are described as influential by participating respondents. In addition to the identification of considerations, there is a potential for expanding the use-cases applicable to them. One such additional use-case that is identified is that of supporting environmental reporting in a future where environmental regulations and requirements become more stringent. Implications – Four main implications are presented. First, that current simulation software is not adequately adapted to include environmental factors. Second, that the starting conditions in an organisation regarding the identified considerations can heavily affect the feasibility of developing and using this type of DSS. Third, that general theory regarding the main use-cases of simulations continues to apply, but that there is a potential for additional use-cases not previously considered. Fourth, that simulation models alone do not necessarily constitute a proper DSS as they in their current form must be augmented by other technical- and organisational systems.