Theory and Practice of Supply Chain Synchronization

In this dissertation, we develop strategies to synchronize component procurement in assemble-to-order (ATO) production and overhaul operations. We focus on the high-tech and mass customization industries which are not only considered to be very important to create or keep U.S. manufacturing jobs, but also suffer most from component inventory burden. In the second chapter, we address the deterministic joint replenishment inventory problem with batch size constraints (JRPB). We characterize system regeneration points, derive a closed-form expression of the average product inventory, and formulate the problem of finding the optimal joint reorder interval to minimize inventory and ordering costs per unit of time. Thereafter, we discuss exact solution approaches and the case of variable reorder intervals. Computational examples demonstrate the power of our methodology. In the third chapter, we incorporate stochastic demand to the JRPB. We propose a joint part replenishment policy that balances inventory and ordering costs while providing a desired service level. A case study and guided computational experiments show the magnitudes of savings that are possible using our methodology. In the fourth chapter, we show how lack of synchronization in assembly systems with long and highly variable component supply lead times can rapidly deteriorate system performance. We develop a full synchronization strategy through time buffering of component orders, which not only guarantees meeting planned production dates but also drastically reduces inventory holding costs. A case study has been carried out to prove the practical relevance, assess potential risks, and evaluate phased implementation policies. The fifth chapter explores the use of condition information from a large number of distributed working units in the field to improve the management of the inventory of spare parts required to maintain those units. Synchronization is again paramount here since spare part inventory needs to adapt to the condition of the engine fleet. All needed parts must be available to complete the overhaul of a unit. We develop a complex simulation environment to assess the performance of different inventory policies and the value of health monitoring. The sixth chapter concludes this dissertation and outlines future research plans as well as opportunities

A fuzzy optimization approach for procurement transport operational planning in an automobile supply chain

We consider a real-world automobile supply chain in which a first-tier supplier serves an assembler and determines its procurement transport planning for a second-tier supplier by using the automobile assembler's demand information, the available capacity of trucks and inventory levels. The proposed fuzzy multi-objective integer linear programming model (FMOILP) improves the transport planning process for material procurement at the first-tier supplier level, which is subject to product groups composed of items that must be ordered together, order lot sizes, fuzzy aspiration levels for inventory and used trucks and uncertain truck maximum available capacities and minimum percentages of demand in stock. Regarding the defuzzification process, we apply two existing methods based on the weighted average method to convert the FMOILP into a crisp MOILP to then apply two different aggregation functions, which we compare, to transform this crisp MOILP into a single objective MILP model. A sensitivity analysis is included to show the impact of the objectives weight vector on the final solutions. The model, based on the full truck load material pick method, provides the quantity of products and number of containers to be loaded per truck and period. An industrial automobile supply chain case study demonstrates the feasibility of applying the proposed model and the solution methodology to a realistic procurement transport planning problem. The results provide lower stock levels and higher occupation of the trucks used to fulfill both demand and minimum inventory requirements than those obtained by the manual spreadsheet-based method. (C) 2014 Elsevier Inc. All rights reserved.This work has been funded partly by the Spanish Ministry of Science and Technology project: Production technology based on the feedback from production, transport and unload planning and the redesign of warehouses decisions in the supply chain (Ref. DPI2010-19977) and by the Universitat Politecnica de Valencia project 'Material Requirement Planning Fourth Generation (MRPIV) (Ref. PAID-05-12)'.Díaz-Madroñero Boluda, FM.; Peidro Payá, D.; Mula, J. (2014). A fuzzy optimization approach for procurement transport operational planning in an automobile supply chain. Applied Mathematical Modelling. 38(23):5705-5725. https://doi.org/10.1016/j.apm.2014.04.053S57055725382

A Review of Aeronautical Fatigue Investigations in Finland May 2021 - April 2023

This document was prepared for the delivery to the 38th Conference of the International Committee on Aeronautical Fatigue and Structural Integrity (ICAF) scheduled to be held in Delft, The Netherlands, 26-29 June 2023.A review is given of the aircraft structural fatigue research and associated activities which form part of the programs within the Air Force Command Finland (AFCOMFIN), the Finnish Defence Force Logistics Command, Joint Systems Centre (FDFLOGCOM JSC), Air Systems Division; Army Command Finland (ARCOMFIN); Aalto University; Arecap Ltd; Elomatic Ltd; Emmecon Ltd; Eurofins Expert Services Oy; Insta ILS Oy; Patria Aviation Oy; Tampere University; Trano Oy; Trueflaw Ltd; and VTT Technical Research Centre of Finland Ltd (VTT).The review summarizes fatigue related research programs and investigations on specific military aircraft since the previous Finnish National Review compiled for the International Committee on Aeronautical Fatigue and Structural Integrity (ICAF) webinar, 30 June 2021

Proceedings of the Conference on Production Systems and Logistics: CPSL 2022

[no abstract available

Testing an AHP model for aircraft spare parts

© 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group. This research aims to develop and test a practical and precise multi-criteria classification of aircraft spare part inventory management, using the Analytical Hierarchy Process (AHP), in order to maintain aircraft operational availability and to reduce unnecessary downtime. In this study, a multi-criteria model is developed within a large-scale aircraft maintenance and repair firm in Indonesia. Spare parts data were extracted from the inventory system and analysed to triangulate the model outcome, demonstrate its validity and compare the results against the mathematical results generated by the system’s algorithm. The findings suggest that AHP can lead to a transparent, rapid and systematic classification model, this is highly accurate and precise with an outcome comparable to traditional methods. The conclusion proposes that the AHP classification model is more effective and transparent than the currently available mathematical methods. This research contributes to the development of the multi-criteria inventory classification literature in the context of the aviation industry

AN EMPIRICAL ANALYSIS OF AUTOMOTIVE MANUFACTURERS SUPPLY CHAIN PERFORMANCE IN CHINA

The research develops a framework for the evaluation of automotive supply chain performance in China. In addition, the research presents indications from a study of Chinese automotive companies with regards to their evaluation and attempts to propose some alternatives for future improvement

Improvement of the Boeing 737 airworthiness system based on the implementation of European aviation regulations

Робота публікується згідно наказу ректора від 29.12.2020 р. №580/од "Про розміщення кваліфікаційних робіт вищої освіти в репозиторії НАУ" . Керівник проекту: доцент, к. т. н. Хімко Андрій Миколайович.One of the fundamental things in the aviation industry is airworthiness. Airworthiness is a characteristic of an aircraft, which is ensured by the principles envisaged and implemented in its design and performance parameters and allows a safe flight to be carried out under the expected conditions and with established operating methods. The expected operating conditions include the range of design conditions defined by the airworthiness standards, as well as the operating limits and recommended flight conditions established for a given aircraft type at the time of certification. Continuing airworthiness of aircraft - one of the most important factors of safety in civil aviation and the efficiency of the air transport industry today. This paper will analyze the use of the airline's Boeing 737 fleet, analyze the reliability system and the maintenance program. Also, the work will pay attention to the analysis of regulatory documents that regulate the activities of organizations for maintenance and Continuing airworthiness. Innovative paperless manufacturing methods are proposed as suggestions for improving the airworthiness system. The issue of improving the system of training professional personnel in this area is also raised, based on the introduction of European aviation regulations