Hanan Hassan Fouad

In serial multi-stage manufacturing systems (SMMS), optimization of part quality inspection planning (PQIP), buffer allocation problem (BAP), and preventive maintenance (PM), individually and jointly, is attracting researchers’ attention. The model formulation for complicated manufacturing systems and the previously mentioned joint decisions is very beneficial given the interdependencies between the various manufacturing functions. As a result, this paper evaluates the literature on joint optimization of the multi-stage serial production system. The literature is classified based on the decision variables basis to represent each manufacturing function [inspection sample size and allocation (PQIP), buffer sizing and allocation (BAP), and preventive maintenance scheduling (PM)], and a general example model is presented in each classification, with a summary of recent studies, solution methods, research gaps, and future research recommendations. In the integrated models, almost all the studies considered only two functions, with that it is worth noting that research into the optimization of over two functions is still in its beginning. Furthermore, most studies neglected many of the real industrial settings that should also be integrated into the model. And finally, there was no specific solution technique recommended in the literature, yet a general simulation optimization method was used to generate and evaluate the combinatorial complex joint models.

Compact installations of solar photovoltaic (PV) systems to maximize the use of land are a necessity in urban regions, where the available installation areas exposed to solar irradiance are limited. Large-scale commercial buildings are typically surrounded by open areas and have busy roofs with mechanical and air conditioning equipment. This study assesses three candidate installation schemes of dual-row near-wall ground-mounted PV systems. The baseline configuration (BC) comprises the classic parallel PV rows. The overhead reflector (OR) configuration adds reflectors above the panels of the second row, to be supported by the wall. The overhead panel (OP) configuration moves the panels of the second row to be above the panels of the first row. Mathematical models are developed to evaluate and optimize the techno-economic performance (in terms of total annual energy production “EPV” and levelized cost of electricity “LCOE”, respectively) based on the tilt angles of the two rows, as well as the length and tilt angle of the reflector in the OR configuration. The results show maximum energy production of 12.54, 12.77, and 12.53 MW for the three configurations, respectively. When the land cost is excluded, the minimum LCOE is 0.0696, 0.0698, and 0.0696 USD/kWh, which correspond to 0.1318, 0.1332, and 0.1182 USD/kWh, respectively, when the land cost is included. The EPV-LCOE Pareto fronts are dominated by different designs of the OR and the OR/OP configurations when excluding and including land cost, respectively, which demonstrates the favorableness of the two proposed schemes, compared to the baseline one.