scholarly journals A Tabu List-Based Algorithm for Capacitated Multilevel Lot-Sizing with Alternate Bills of Materials and Co-Production Environments

2019 ◽  
Vol 9 (7) ◽  
pp. 1464 ◽  
Author(s):  
Alfonso Romero-Conrado ◽  
Jairo Coronado-Hernandez ◽  
Gregorio Rius-Sorolla ◽  
José García-Sabater
Keyword(s):  
Lot Sizing ◽  
Medium Size ◽  
Exact Methods ◽  
Operations Planning ◽  
Material Requirements Planning ◽  
Tabu List ◽  
Production Environments ◽  
Lot Sizes ◽  
Multi Level ◽  
Definition Of

The definition of lot sizes represents one of the most important decisions in production planning. Lot-sizing turns into an increasingly complex set of decisions that requires efficient solution approaches, in response to the time-consuming exact methods (LP, MIP). This paper aims to propose a Tabu list-based algorithm (TLBA) as an alternative to the Generic Materials and Operations Planning (GMOP) model. The algorithm considers a multi-level, multi-item planning structure. It is initialized using a lot-for-lot (LxL) method and candidate solutions are evaluated through an iterative Material Requirements Planning (MRP) procedure. Three different sizes of test instances are defined and better results are obtained in the large and medium-size problems, with minimum average gaps close to 10.5%.

scholarly journals Combining population-based and exact methods for multi-level capacitated lot-sizing problems

2006 ◽  
Vol 44 (22) ◽  
pp. 4755-4771 ◽  
Author(s):  
Rapeepan Pitakaso ◽  
Christian Almeder ◽  
Karl F. Doerner ◽  
Richard F. Hartl
Keyword(s):  
Lot Sizing ◽  
Population Based ◽  
Exact Methods ◽  
Capacitated Lot Sizing ◽  
Multi Level

scholarly journals Language Family Engineering with Product Lines of Multi-level Models

2021 ◽  
Author(s):  
Juan de Lara ◽  
Esther Guerra
Keyword(s):  
Software Engineering ◽  
Arbitrary Number ◽  
Formal Theory ◽  
The Other ◽  
Language Family ◽  
Top Down ◽  
Product Lines ◽  
Modelling Languages ◽  
Multi Level ◽  
Definition Of

AbstractModelling is an essential activity in software engineering. It typically involves two meta-levels: one includes meta-models that describe modelling languages, and the other contains models built by instantiating those meta-models. Multi-level modelling generalizes this approach by allowing models to span an arbitrary number of meta-levels. A scenario that profits from multi-level modelling is the definition of language families that can be specialized (e.g., for different domains) by successive refinements at subsequent meta-levels, hence promoting language reuse. This enables an open set of variability options given by all possible specializations of the language family. However, multi-level modelling lacks the ability to express closed variability regarding the availability of language primitives or the possibility to opt between alternative primitive realizations. This limits the reuse opportunities of a language family. To improve this situation, we propose a novel combination of product lines with multi-level modelling to cover both open and closed variability. Our proposal is backed by a formal theory that guarantees correctness, enables top-down and bottom-up language variability design, and is implemented atop the MetaDepth multi-level modelling tool.

A Multi-Class Multi-Level Capacitated Lot Sizing Model

2000 ◽  
Vol 51 (11) ◽  
pp. 1309 ◽  
Author(s):  
Y.-F. Hung ◽  
K.-L. Chien
Keyword(s):  
Lot Sizing ◽  
Capacitated Lot Sizing ◽  
Multi Level

A New Type of Gas Turbine Based-Hybrid Propulsion System: Part 1—Concept Development, Definition of Mission Parameters and Preliminary Sizing

2000 ◽  
Author(s):  
Emiliano Cioffarelli ◽  
Enrico Sciubba
Keyword(s):  
Gas Turbine ◽  
Combustion Engine ◽  
Development Program ◽  
Propulsion System ◽  
Medium Size ◽  
Passenger Cars ◽  
Worst Case ◽  
Hybrid Propulsion ◽  
Wide Range ◽  
Definition Of

Abstract A hybrid propulsion system of new conception for medium-size passenger cars is described and its preliminary design developed. The system consists of a turbogas set operating at fixed rpm, and a battery-operated electric motor that constitutes the actual “propulsor”. The battery pack is charged by the thermal engine which works in an electronically controlled on/off mode. Though the idea is not entirely new (there are some concept cars with similar characteristics), the present study has important new aspects, in that it bases the sizing of the thermal engine on the foreseen “worst case” vehicle mission (derived from available data on mileage and consumption derived from road tests and standard EEC driving mission cycles) that they can in fact be accomplished, and then proceeds to develop a control strategy that enables the vehicle to perform at its near–peak efficiency over a wide range of possible missions. To increase the driveability of the car, a variable-inlet vane system is provided for the gas turbine. After developing the mission concept, and showing via a thorough set of energy balances (integrated over various mission profiles), a preliminary sizing of the turbogas set is performed. The results of this first part of the development program show that the concept is indeed feasible, and that it has important advantages over both more traditional (Hybrid Vehicles powered by an Internal Combustion Engine) and novel (All-Electric Vehicle) propulsion systems.

scholarly journals Dynamic lot sizing problem under uncertainty of returned products in remanufacturing industry

2018 ◽  
Vol 204 ◽  
pp. 07005
Author(s):  
Iman Setyoaji
Keyword(s):  
Bayesian Inference ◽  
Lot Sizing ◽  
Replacement Ratio ◽  
Total Cost ◽  
Lot Sizing Problem ◽  
Holding Cost ◽  
Dynamic Lot Sizing ◽  
Lot Sizes

Remanufacturing processes face uncertainty in the quality of the items being returned by customers, this significant variability complicates the control of inventories. Demands can be satisfied by procured new items, but also by remanufactured returned items. This paper develops dynamic lot sizing model for remanufacturing industry under uncertainty of returned items and proposes Bayesian Inference to estimate the replacement ratio of returned items that used to determine those lot sizes for new items. The objective of this paper is to minimize the total cost composed of holding cost and set-ups cost. A numerical example is provided based on case study. The result shows that total cost is reduced to be 45%.

scholarly journals FLOWER POLLINATION ALGORITHM FOR MULTI LEVEL LOT SIZING OPTIMIZATION

2021 ◽  
Vol 9 (1) ◽  
pp. 127-133
Author(s):  
V. V. D. Sahithi, M. Srinivasa Rao, C. S. P. Rao
Keyword(s):  
Lot Sizing ◽  
Complex Problem ◽  
Flower Pollination Algorithm ◽  
Customer Requirements ◽  
Proper Place ◽  
Flower Pollination ◽  
Multi Level ◽  
Simulation Results ◽  
Exact Amount ◽  
Better Than

In this competitive and constantly changing world, meeting the customer requirements within less time by providing less cost is extremely tricky task. This is only possible by optimizing all the different parameters in its life cycle. Here Optimizing the inventory plays a major role.Maintaining the exact amount of inventory, at proper place, in appropriate level is a challenging task for production managers. When we work on Multi level environments this problem becomes even more complex.So, to optimize this kind of problems we applied binary form of Flower Pollination algorithm to solve this complex problem. we solved different inventory lot sizing problems with this FP algorithm and compared the results with genetic algorithm and other algorithms. In all the scenarios our simulation results shown that FP algorithm is better than other algorithms.                       

scholarly journals ANALISIS PERENCANAAN BAHAN BAKU DI UD. AA DENGAN MENERAPKAN METODE MATERIAL REQUIREMENT PLANNING (MRP)

2020 ◽  
Vol 5 (1) ◽  
pp. 1-12
Author(s):  
Rudi Abdika Saputra ◽  
Inna Kholidasari ◽  
Susanti Sundari ◽  
Lestari Setiawati
Keyword(s):  
Lot Sizing ◽  
Raw Materials ◽  
Raw Material ◽  
Production Schedule ◽  
Material Requirements Planning ◽  
Forecasting Method ◽  
Material Requirement Planning ◽  
Material Requirement ◽  
Material Procurement ◽  
Master Production Schedule

This study discusses the application of the material requirements planning (MRP) method in the planning of raw materials in a furniture company. The purpose of this research is to know the planning of raw materials for furniture products in UD. AA, determine the most suitable inventory model to be applied to material inventory planning and analyze the role of the MRP system in raw material procurement planning. The forecasting method used is the quantitative method of time series analysis, determining the master production schedule, calculating lot sizing (LFL, EOQ, POQ methods). From determining the Master Production Schedule, it is found that the cabinet production plan for the next three months is 4 units per period or week, and based on the calculation of Material Requirement Planning (MRP) it can be seen what components are needed for the manufacture of cabinets, how many and when each component is required. Therefore it is obtained that the total raw material requirement for wood for the next three months is 11.34 m³.

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