## 6 Designing, Balancing and Scheduling Assembly Lines with Uncertain Parameters
### A Robust Approach to the ALBP with Uncertain Parameters  
A design for a disassembly line is the essential procedure in determining the disassembly and recyclability of the end-of-life products. An efficient procedure aims to provide the disassembling and recycling. The recent trends of disassembling and recycling include environmental and social sustainability. Due to a shortage of energy and deterioration of the ecological environment, the sustainable production is an active research topic to use the economic benefits as the evaluation standard of a design scheme and environmental characteristics. The paper [115] provides an approach for designing a disassembly line based on sustainability. A hybrid multi-attribute decision-making algorithm integrating the regret theory and the entropy weighting procedure was developed. To implement the proposed algorithm, several criterions were used (disassembly energy consumption, disassembly accessibility, fastener ratio, toxic material proportion, material recovery rate, disassembly expense, waste emissions, production and use noise). To better describe the fuzziness of human thinking and to avoid a loss of information and distortion during information aggregation phases, the evaluation information given by experts was presented by the interval linguistic intuition of fuzzy numbers. The weighted vector of the index structure was determined by the entropy weighting procedure under a fuzzy environment. The regret theory was employed to obtain a final order of alternatives via considering and guaranteeing the risk attitude and the regret attitude of experts. To show the applicability of the developed algorithm, a case study including four kinds of refrigerator schemes was conducted to validate the proposed algorithm. A comparison with other algorithms along with a sensitivity and stability analysis of experiments was executed to verify the effectiveness and reliability of the developed algorithm. The computational experimental results showed that disassembly accessibility, the fastener ratio, waste emissions and disassembly energy consumption have a large impact on the scheme selection based on sustainability. The proposed algorithm outperforms other tested ones. The chosen scheme was a winner in majority of the sensitivity and stability analyses. Robotic disassembly sequence planning is a research area that looks at the sequence of actions in the disassembly intending to achieve autonomous disassembly with high efficiency and low cost in remanufacturing and recycling applications. Key information being factored in disassembly sequence planning is the interference condition of a product (a mathematical representation of the spatial location of components in the assembly in the form of a matrix). An observed challenge is that the interference condition can be uncertain due to variations in the end-of-life conditions. Therefore, there is a lack of tools available in disassembly sequence planning under uncertain interference. To address this challenge, in [116], a disassembly sequence planning algorithm is proposed that can cope with uncertain interference conditions enabled by the fuzzification of disassembly sequence planning. This algorithm is a fuzzy and dynamic modeling one, in combination with an iterative re-planning strategy. The fuzzification of disassembly sequence planning offers the capability for the disassembly sequence to adapt to failures and self-evolve online. Three disassembly products were used to demonstrate the properties of this algorithm. In [21], the case of the ALBP-1 is considered, in which assembly operation durations are worker-dependent and uncertain, and being expressed as segments (closed intervals) of possible duration values. The main goal is to find an assignment of assembly operations and workers to a minimal number of used workstations such that the resulting productivity level is in respect to a desired robust measure.