Aggregate Nesting: Transforming Multi-Material Dynamic Allocation for Cost-Effective Manufacturing

Waste material affects project implementation. In addition, it also affects the productivity of the project as well as costs and time. Based on this, good management is needed in handling and minimizing the occurrence of material waste. Lean Construction is one approach that can be used to handle and minimize this occurrence. This study aims to determine the most dominant waste material indicators that cause material waste, determine the estimated costs resulting from material waste and total cost estimates until the observed work is completed, determine the most dominant type of material that causes material waste and determine the percentage of Lean Construction implementation. The case study of this research was conducted on the Karangsambung Indonesia Geodiversity Area Facility Development Project Package 2. The Bayes theorem method was used to determine the most dominant indicator of material waste that causes material waste to occur. Pareto diagrams are used to determine the most dominant type of material that causes material waste. The data from this study were obtained by conducting interviews, observations and filling out the waste material questionnaire and the Lean Construction application questionnaire. The conclusion of this study is that the most dominant indicators that cause material waste are Defect and Waiting with a confidence value of 100% each. The estimated cost obtained during the 2-week observation is Rp. 10,440,859.91 and the estimated cost until the work is completed is Rp. 26,102,149,77. The most dominant type of material that causes material waste is deformed reinforcement Ø22 (Rp. 4,436,673.32), deformed reinforcement Ø 19 (Rp. 2,051,606 ,29) and threaded reinforcement Ø 16 (Rp. 1,387,546,88). The percentage of Lean Construction implementation obtained is 98.94%.

Accurate quality, time and budget have become a reference for the success of a project. However, the presence of waste, especially waste of materials, which cannot be handled properly, can cause cost overruns and overtime. Upper structure work is vulnerable to producing waste, so waste control must be carried out. This research aims to calculate waste levels and waste costs using the Eliminate Waste principle, identify factors that cause waste of material and create control recommendations. The research results show that the highest waste level is found in D22 threaded iron at 7.59%, and the lowest is in D10 threaded iron at 0.40%; regarding the highest waste cost, it is found in D22 Threaded Iron as much as IDR 533,908,298.14,-, while the lowest waste cost is in D8 Threaded Iron as much as IDR 461,886.83,-. Factors that cause material waste are damaged material conditions, rework or repair, errors in cutting material, errors in reading shop drawings, lack of measuring tool productivity, inappropriate use of tools, lack of coordination, lack of supervisory management and lousy weather. Control recommendations include monitoring material quality, strengthening supervisory management, ensuring the appropriateness of material storage, coordinating between parties, reading shop drawings before starting work, working according to SOPs, providing worker expertise, checking the accuracy of implementation methods, ensuring equipment suitability, measuring tool productivity, carrying out maintenance the right tools, training workers, creating good cooperation, scheduling meetings every week, preparing material covers in case of rain, and separate storage of vulnerable materials.

This article considers scheduling products in a parallel, non-identical machine environment subject to sequence-dependent setup costs and sequence-dependent setup times, where production waste and processing time of a product depend on feasible machine assignments. A Mixed-Integer Programming (MIP) formulation is developed that captures trade-offs between overtime labor costs and waste costs. Two solution procedures are developed to address large problem instances. One procedure is an algorithm that determines a vector of product-to-machine assignments that assists an MIP solver to find an initial feasible solution. The second procedure is a decomposition heuristic that iteratively solves a relaxed subproblem and uses the subproblem solution to fix assignment variables in the main MIP formulation. In addition, bounds on the quality of solutions found using the decomposition heuristic are presented. Experiments are conducted that show the developed formulation outperforms more traditional scheduling objectives with respect to the waste and overtime labor costs. Additional experimentation investigates the effects that problem parameter values have on total waste and labor costs, performance of the approaches, and the use of overtime labor.

The Influence of Raw Material on the Wood Product Manufacturing

The quality of cast components is critical in manufacturing industries, as defects such as cold shuts lead to increased rejection rates, material waste, and production costs. This study employs Response Surface Methodology (RSM) to optimize key sand casting process parameters — pouring temperature, pouring time, moisture content, and mold hardness — in order to minimize cold shut defects. A Central Composite Design (CCD) was used to analyze parameter interactions and determine the optimal settings. The regression model demonstrated strong predictive accuracy with an R2 value of 86.03%, while Analysis of Variance (ANOVA) confirmed the statistical significance of the results. Experimental validation showed a 45% reduction in cold shut defects. These findings highlight RSMs effectiveness as a robust tool for process optimization and quality improvement in casting operations, offering a practical framework for defect reduction and enhanced productivity in industrial applications.

Purpose The purpose of this study is to propose a trajectory generation method for 6 degrees of freedom manipulators that simultaneously optimizes all joint motions for point to point and multipoint tasks. Conventional methods treat each joint independently and synchronize to the slowest, often leading to suboptimal execution time and motion smoothness. The goal is to improve time efficiency and dynamic performance in industrial robotics by leveraging joint-level kinematic constraints. Design/methodology/approach A nonlinear optimization problem is formulated using quintic B-spline interpolation to generate smooth joint trajectories under velocity, acceleration and jerk limits. Segment durations for all joints are optimized simultaneously. The interior-point method is used to solve the problem. The approach is validated through simulation and physical execution on the Dobot Nova5 manipulator using benchmark point-to-point and multipoint motion tasks. Findings The proposed method yields trajectories up to 39% faster than conventional methods in point-to-point tasks. It produces smoother motions with lower peak and average jerk values, improving execution quality. In multipoint scenarios, the method reduces execution time by 3.26% compared to the synchronous B-spline method. Both simulation and experimental results confirm the method’s effectiveness and accuracy. Comparative analysis with recent trajectory planning methods further demonstrates the proposed method’s superior C2 continuity and smooth motion characteristics. Research limitations/implications The proposed trajectory optimization method considers only kinematic constraints, excluding dynamic factors such as torque limits, payload effects and actuator saturation. The framework assumes offline planning under fixed task conditions, limiting adaptability in dynamic environments. Obstacle avoidance is handled via predefined waypoints rather than integrated constraints. Although quintic B-splines offer a balance between smoothness and computational efficiency, alternative spline orders may improve performance in specific contexts. Future work will address dynamic modeling, real-time replanning and integration with collision-aware path planning to enhance practical applicability. Practical implications The proposed method enables smooth, time-optimal trajectory generation for robotic manipulators without synchronizing all joints to the slowest one, improving motion efficiency and productivity. Its asynchronous formulation allows better utilization of joint capabilities under kinematic constraints. By supporting both point-to-point and multipoint tasks, the approach is applicable to a wide range of industrial assembly operations. The method has been validated through hardware experiments, demonstrating consistent execution and repeatability. It can be readily integrated with existing robot controllers and extended with via point-based obstacle avoidance for constrained environments. Social implications The proposed trajectory planning method enhances the operational efficiency of robotic manipulators, contributing to increased automation in manufacturing and assembly tasks. By enabling smoother, faster and more reliable robot motion, it supports safer and more collaborative work environments, especially in human−robot shared workspaces. Improved efficiency and accuracy in industrial processes may reduce energy consumption, material waste and production costs. This advancement supports broader goals of sustainable automation and makes advanced robotics more accessible for small and medium enterprises, potentially impacting workforce roles and productivity in evolving industrial landscapes. Originality/value Unlike traditional decoupled methods, this unified framework globally optimizes all joint motions using quintic B-splines under kinematic constraints. The method is adaptable across robotic platforms and suitable for computer numerical control feedrate planning. It enables smooth and time-efficient trajectories for advanced industrial applications.

Material is one of the important components that has a close influence on the cost of a project, so with a large amount of construction material waste, it can be said that there is an overrun in the financing sector. In addition, the remaining construction materials can produce a high percentage of environmental pollution. Residual material or construction waste is something that is never separated from a project development. The existence of leftover materials can have a negative effect on the environment around the construction project. The remaining material can be interpreted as part of the material that has not been used resulting from the process of construction, repair, change or any item produced from the process, or an accident that cannot be directly used in that place without any further treatment. The railway bridge construction project certainly requires various types of materials, when viewed from the concept for the use of large materials, the more the remaining materials that exist or become construction waste. This research aims to determine the quantity of material waste generated from the construction of the railway bridge and analyze the factors that cause material waste in the railway bridge construction project. This research method uses observation and interview techniques and is supported by data obtained from the research location. The results of this study show that the largest percentage of waste cost during the railway bridge construction project came from K300 concrete material for retaining walls in the amount of 16.714% or Rp. 6,283,720.00. The source of the cause of the remaining material where the factors are generated from project actors, design, measurement/calculation, management, implementation and procurement/handling of materials.

In previous chapters, only single objective tasks were addressed. However, multiple goals are common in real-world domains. For instance, a company typically desires to increase sales while reducing production costs. Within its marketing department, the goal might include maximizing target audiences while minimizing the marketing budget. Also, within the production department, the same company might want to maximize the manufactured items, in terms of both quality and production numbers, while minimizing production time, costs, and waste of material. Often, the various objectives can conflict, where gaining in one goal involves losing in another one.

In conventional cutting system of Heat-Shrink-Tube, workers operate cutting system after considering about length and quantity of heat-shrink-tube. So, not only work time and production cost is increased but also material is wasted because the data that workers have to consider is so much. In this paper, an effective cutting system of heat-shrink-tube was developed to reduce production cost, work time and waste of material. The cutting system consists of a supervisory computer installed inside a control room, a on-site computer installed on the work area, and a PLC system. In the developed system, a supervisory computer send work order to the on-site computer using LAN and the on-site computer operates the cutting system of the heatshrink-tube after it makes an array production order. Also, the on-site computer reports information to the supervisory computer when an accident happened.

As an educational city, Jatinangor has a fairly large population density. In turn, it generates restaurant organic waste in large quantities. Excessive production of organic waste will be a problem if it is not accompanied by good management and utilization. One of the efforts in utilizing restaurant waste is to turn the waste as fish feed. This study aims to calculate the production of restaurant waste and analyze the cost of production of fish feed using restaurant waste flour. The production of restaurant waste was calculated using purposive random sampling, while the cost of feed production was determined by using variable costing method. Questionnaires and research primary data were used to collect data. The results obtained from this study were as such: production of restaurant waste in the Jatinangor area is 261.7 Kg/day, the cost of production for fish feed with the basic ingredients of restaurant waste flour is 70,013,127 IDR with a production capacity of 6,913.1 kg of fish feed per year, so that the cost of feed per kilogram is 10,127.60 IDR, and the selling price of feed is 12,200 IDR/kilogram with a profit of 20%. Thus, it can be seen that independent feed production using restaurant waste can be a solution in the utilization of waste and can also be used as a source of income for the surrounding community.

Influence of Geometrical Ratios in Forgeability of Complex Shapes during Hot Forging of Ti-6Al-4V Titanium Alloy

The manufacturing sector accounts for a large percentage of global energy use and greenhouse gas emissions, and there is growing interest in the potential of additive manufacturing (AM) to reduce the sector's environmental impacts. Across multiple industries, AM has been used to reduce material use in final parts by 35-80%, and recent publications have predicted that AM will enable the fabrication of customized products locally and on-demand, reducing shipping and material waste. In many contexts, however, AM is not a viable alternative to traditional manufacturing methods due to its high production costs. And in high-volume mass production, AM can lead to increased energy use and material waste, worsening environmental impacts compared to traditional production methods. Whether AM is an environmentally and economically preferred alternative to traditional manufacturing depends on several hidden aspects of AM that are not readily apparent when comparing final products, including energy-intensive and expensive material feedstocks, excessive material waste during production, high machine costs, and slow rates of production. We systematically review comparative studies of the environmental impacts and costs of AM in contrast with traditional manufacturing methods and identify the conditions under which AM is the environmentally and economically preferred alternative. We find that AM has lower production costs and environmental impacts when production volumes are relatively low (below ∼1,000 per year for environmental impacts and below 42-87,000 per year for costs, depending on the AM process and part geometry) or the parts are small and would have high material waste if traditionally manufactured. In cases when the geometric freedom of AM enables performance improvements that reduce environmental impacts and costs during a product's use phase, these can counteract the higher production impacts of AM, making it the preferred alternative at larger production volumes. AM's ability to be environmentally and economically beneficial for mass manufacturing in a wider variety of contexts is dependent on reducing the cost and energy intensity of material feedstock production, eliminating the need for support structures, raising production speeds, and reducing per unit machine costs. These challenges are not primarily caused by economies of scale, and therefore, they are not likely to be addressed by the increasing expansion of the AM sector. Instead, they will require fundamental advances in material science, AM production technologies, and computer-aided design software.

Composite materials have been increasingly used in various branches of industry, transport, construction, and medicine-as well as in other sectors of the economy and science-in recent decades. A significant advancement in the improvement of composite material characteristics has been achieved through the use of nanoparticles, which substantially enhance the properties of the base material, whether it is the matrix or the reinforcing phase in hybrid composites. The broad application of polymers and polymer composites in many areas of engineering has had a significant impact on reducing friction and wear, improving the thermal characteristics of individual components and entire technical systems, enhancing electrical conductivity, reducing the specific weight of components, lowering noise and vibration levels, and ultimately decreasing fuel consumption, production costs, and the costs of operation and maintenance of technical systems. This paper explores the potential applications of polymer composites in various assemblies and components of conventional vehicles, as well as in hybrid and electric vehicles. Furthermore, their use in medicine and the defense industry is examined-fields in which some authors believe composites were first pioneered. Finally, aviation represents an indispensable domain for the application of such materials, presenting unique exploitation boundary conditions, including dynamic environmental changes such as variations in temperature, pressure, velocity, and direction, as well as the need for high levels of protection. Future research can be unequivocally focused on the structural and technological advancement of polymer composites, specifically through optimization aimed at reducing waste and lowering production costs.

Casting is the best and effective technique used for manufacturing products. The important accessory for casting is furnace. Furnace is used to melt the metal. A perfect furnace is one that reduces the wastage of material, reduces the cost of manufacturing and there by reduces the cost of production. Of all the present day furnaces there may be wastage of material, and the chances of increasing the time of manufacturing as the is continuous need of tilting of the furnace for every mould and then changing the moulds. Considering these aspects, a simple and least expensive tilting rotary furnace is designed and developed. The Tilting and Rotary Furnace consists of mainly melting chamber and the base. The metal enters the melting chamber through the input door that is provided on the top of the melting chamber. Inside the melting chamber there is a graphite furnace. The metal is melted in the graphite crucible. An insulation of ceramic fibre cloth is provided inside the furnace. The metal is melted using Propane gas. The propane gas is easily available and economic. The gas is burned using a pilot burner. The pilot burner is more efficient that other burners. The pilot burner is lit with a push button igniter. The pilot burner is located at the bottom of the combustion chamber. This enables the uniform heating of the metal inside the crucible. The temperature inside the melting chamber is noted using a temperature sensor. The gas input is cut-off if the temperature is exceeding a specific temperature. After the melting of the metal is done the furnace is tilted and after the mould is filled it is rotated. The external gears are used to controlling the tilting. The results of studies carried out for the design & development of low cost, simple furnace that can be mounted anywhere on the shop floor and this can be very much useful for the education purposes and small scale manufacturing. The furnace can be rotated in 360 degrees and can help in reducing the time taken in manufacturing. The furnace is provided with a rotation motion to the base which helps in providing a uniform distribution of molten metal to various moulds and can be used to fill a number of moulds with minimal wastage of the molten material. Due to the tilting action provided to the combustion chamber, the flow of metal can be controlled easily during pouring of molten metal into the moulds.

Hybrid heuristic algorithms are proposed for the nesting of two-dimensional rectangular parts in multiple plates. The nesting algorithm of Babu and Babu is first modified and a new heuristic nesting algorithm, IBH, is proposed to utilize the material plate further. IBH is then combined in a meta-heuristic approach, simulated annealing. The proposed hybrid algorithms can then be extended to solve the nesting problem involving irregular parts by embedding irregular parts to rectangles. One problem arises in this 'irregular-to-rectangular' process, i.e. conversion of demands of the original irregular parts into demands of the embedding rectangles. A greedy heuristic rule is therefore presented to determine the number of embedding rectangles of different types to be used in order to maximize the utilization of the material plate given that the demand of each irregular part must be satisfied. Promising computational results are obtained and reported by running examples from the literature and data relevant to the footwear industry.