Optimal Schedule of a Dairy Manufactory

This paper deals with short-term scheduling of the dairy industry. Two different approaches are proposed for obtaining the minimal makespan schedules. According to the first, S-graph framework is proposed to find the optimal solution of the flow-shop scheduling problem. The problem is solved by applying the branch and bound technique. The second approach uses the integer programming formulation of the scheduling problem and BASIC genetic algorithm has been used to solve the optimization problem. Both approaches take into consideration volumes of units assigned to perform tasks, and respective size factors that affect the size of batches and their number must be produces to achieve production goals and thus on the schedules duration. Manufacturing of two type curds is used as a case study. The results obtained show that both approaches provide comparable solutions. Both approaches could be seen as a good alternative to project manager to find appropriate schedule of the dairy industry

Weldability of Duplex Stainless Steels - Thermal Cycle and Nitrogen Effects : Duplex stainless steel weld microstructures were investigated as a function of weld thermal cycles and shielding gas nitrogen content

Much development work has been performed worldwide on the welding of duplex stainless steels (DSSs), where losses in base metal nitrogen during welding have been compensated by filler metal and nitrogen additions to the shielding gas. However, some heat-affected zone (HAZ) microstructural changes have not always responded consistently to nitrogen mixtures added to the shielding gas. In this work, DSS weld microstructures were investigated as a function of weld thermal cycles and shielding gas nitrogen content. Physical simulations, actual gas tungsten arc welding (GTAW) in controlled atmospheres, and entrapped nitrogen measurements were used to relate to the weld austenite-to-ferrite (A/F) phase ratios. Results showed the thermal cycles had a stronger effect on the weld A/F ratio than shielding gas nitrogen content. Physical simulations and actual GTAW trials also showed the A/F ratio changes in the opposite way in the fusion zone than in the HAZ. Reheating was also found to have an important effect on the microstructure. The above findings should allow fabricators to better design the welding process with DSS. Better control of nitrogen-containing shielding gas mixtures, along with heat input limitations, should result in more consistent weld properties and wider use of DSS by industry

Methodology – A Review of Intelligent Manufacturing Scope, Strategy and Simulation

This paper presents a critical review of some existing modelling, control and optimization techniques for energy saving, carbon emission reduction in manufacturing processes. The study on various production issues reveals different levels of intelligent manufacturing approaches. Then methods and strategies to tackle the sustainability issues in manufacturing are summarized. Modelling tools such as discrete (dynamic) event system (DES/DEDS) and agent-based modelling/simulation (ABS) approaches are reviewed from the production planning and control prospective. These approaches will provide some guidelines for the development of advanced factory modelling, resource flow analysis and assisting the identification of improvement potentials, in order to achieve more sustainable manufacturing