A decision model for selecting parts feeding policies in assembly lines

2015 ◽  
Vol 115 (6) ◽  
pp. 974-1003 ◽  
Author(s):  
Antonio C. Caputo ◽  
Pacifico M. Pelagagge ◽  
Paolo Salini
Keyword(s):  
Cost Effective ◽  
Just In Time ◽  
Successful Implementation ◽  
Assembly Lines ◽  
Content Type ◽  
Optimal Mix ◽  
Consistent Basis ◽  
Early Decision ◽  
Optimal Material ◽  
Parts Feeding

Purpose – The purpose of this paper is to develop an optimization model allowing the choice of parts feeding policy to assembly lines in order to minimize total cost. Design/methodology/approach – An integer linear programming mathematical model is developed to assign the optimal material feeding policy to each part type. The model allows choice between kitting, line stocking and just in time delivery policies. Findings – The choice of assembly lines feeding policy is not trivial and requires a thorough economic comparison of alternatives. It is found that a proper mix of parts feeding policies may be better that adopting a single material delivery policy for all parts. Research limitations/implications – The model is aimed at single-model assembly lines operating in a deterministic environment, but can be extended to the multi-model line case. While relevant quantitative cost drivers are included, some context-related qualitative factors are not included yet. The model assumes that information about product structure and part requirements are known and that a preliminary design of the assembly system has been carried out. Practical implications – Production managers are given a quantitative-decision tool to determine the optimal mix of material supply policies at an early decision stage. Originality/value – Respect previous simplified literature models, this approach allows to quantify a number of additional factors which are critical for successful implementation of cost-effective parts feeding systems, allowing comparison of alternative policies on a consistent basis.

Planning models for continuous supply of parts in assembly systems

2015 ◽  
Vol 35 (1) ◽  
pp. 35-46 ◽  
Author(s):  
Antonio C. Caputo ◽  
Pacifico M. Pelagagge ◽  
Paolo Salini
Keyword(s):  
Cost Effective ◽  
Successful Implementation ◽  
Total System ◽  
Assembly Lines ◽  
Content Type ◽  
Industrial Setting ◽  
Trade Offs ◽  
Planning Models ◽  
Early Decision ◽  
Continuous Material

Purpose – The purpose of this paper is to develop analytical planning models to compare just-in-time (JIT) delivery and line storage (LS) alternatives for a continuous supply of materials to assembly lines. Design/methodology/approach – A mathematical model is developed to size resources and to determine total system costs. Findings – The choice of assembly lines feeding policy requires a thorough economic comparison of alternatives. However, the existing models are often simplistic, neglecting many critical factors which affect the systems’ performances. As a consequence, industries are unsure about which system is best for their environment. This model allows to compare the cost and suitability of two major continuous-supply alternatives in any specific industrial setting. Results of the model application are case-specific and cannot be generalized. Research limitations/implications – The model is aimed at single-model assembly lines operating in a deterministic environment. Although relevant quantitative cost drivers are included, some context-related qualitative factors are not yet included. The model assumes that the information about product structure and part requirements is known and that a preliminary design of the assembly system has been carried out. Practical implications – Production managers are given a quantitative decision tool to properly assess the implementation of continuous material supply policies at an early decision stage, and determine which option is the best, also allowing to explore trade-offs between the alternatives. Originality/value – With respect to previous simplified literature models, this new approach allows to quantify a number of additional factors which are critical for the successful implementation of cost-effective continuous-supply systems, including error costs. No other direct comparison of LS and JIT is available in the literature.

A model for kitting operations planning

2015 ◽  
Vol 35 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Antonio C. Caputo ◽  
Pacifico M. Pelagagge ◽  
Paolo Salini
Keyword(s):  
Cost Estimation ◽  
Mixed Model ◽  
Operating Costs ◽  
Successful Implementation ◽  
Total System ◽  
Assembly Lines ◽  
Content Type ◽  
Work In Process ◽  
Trade Offs ◽  
Quality Costs

Purpose – The aim of this paper is to develop a detailed descriptive model for kitting operations, allowing resources sizing and computation of systems’ economic performances. Design/methodology/approach – A mathematical model allows to size resources, given product characteristics and production mix, and determines total system costs by assessing relevant cost items including investment costs (vehicles, containers, storage racks), direct operating costs (transport and kitting workforce, vehicles energy consumption and maintenance, quality costs), indirect operating costs (space requirements, work in process (WIP) and safety stock holding costs, administration and control). Findings – The choice of parts delivery supply to assembly lines requires a thorough economic comparison of alternatives. However, existing models are often simplistic and neglect many critical factors which affect the systems’ performances. As a consequence, industries are unsure about which system is best for their environment. This model allows assessment of the cost and suitability of kitting in any specific industrial setting. Results of the model application are case-specific and cannot be generalized, but the major impact of labour and error correction cost has been highlighted. Research limitations/implications – The model at present focusses on the in-house kitting systems based on travelling kits concept only. Although all quantitative cost drivers are included, some context-related qualitative decision factors are not yet included. The model assumes that the information about product structure and part requirements is known and that a preliminary design of the assembly system (i.e. line balancing) has been carried out. Practical implications – Production managers are given a quantitative decision tool to properly assess the implementation of kitting policies at an early decision stage. This allows exploring the trade-offs between the alternatives and properly planning the adoption of kitting systems, as well as comparing kitting with alternative material supply methods. Originality/value – With respect to previous simplified literature models, this new approach allows quantification of a number of additional factors which are critical for successful implementation of cost-effective kitting systems, including kitting errors. An exhaustive cost estimation of kitting systems in multiple, mixed-model assembly lines is thus permitted.

Scheduling the in-house logistics distribution for automotive assembly lines with just-in-time principles

2017 ◽  
Vol 37 (1) ◽  
pp. 51-63 ◽  
Author(s):  
Binghai Zhou ◽  
Tao Peng
Keyword(s):  
Real World ◽  
Approximate Solutions ◽  
Distribution Model ◽  
Small Scale ◽  
Just In Time ◽  
Similar Distribution ◽  
Assembly Lines ◽  
Content Type ◽  
Bee Colony ◽  
Automotive Assembly

Purpose This paper aims to investigate the just-in-time (JIT) in-house logistics problem for automotive assembly lines. A point-to-point (P2P) JIT distribution model has been formulated to specify the destination station and parts quantity of each delivery for minimizing line-side inventory levels. Design/methodology/approach An exact backtracking procedure integrating with dominance properties is presented to cope with small-scale instances. As for real-world instances, this study develops a modified discrete artificial bee colony (MDABC) metaheuristic. The neighbor search of MDABC is redefined by a novel differential evolution loop and a breadth-first search. Findings The backtracking method has efficaciously cut unpromising branches and solved small-scale instances to optimality. Meanwhile, the modifications have enhanced exploitation abilities of the original metaheuristic, and good approximate solutions are obtained for real-world instances. Furthermore, inventory peaks are avoided according to the simulation results which validates the effectiveness of this mathematical model to facilitate an efficient JIT parts supply. Research limitations/implications This study is applicable only if the breakdown of transport devices is not considered. The current work has effectively facilitated the P2P JIT logistics scheduling in automotive assembly lines, and it could be modified to tackle similar distribution problems featuring time-varying demands. Originality/value Both limited vehicle capacities and no stock-outs constraints are considered, and the combined routing and loading problem is solved satisfactorily for an efficient JIT supply of material in automotive assembly lines.

How QR codes permit access to key information

2017 ◽  
Vol 31 (5) ◽  
pp. 32-35
Keyword(s):  
Design Methodology ◽  
Time Characteristic ◽  
Just In Time ◽  
Successful Implementation ◽  
Quick Response ◽  
Qr Codes ◽  
Content Type ◽  
Internet Connection ◽  
Pertinent Information ◽  
Practical Implications

Purpose This paper aims to review the latest management developments across the globe and pinpoint practical implications from cutting-edge research and case studies. Design/methodology/approach This briefing is prepared by an independent writer who adds their own impartial comments and places the articles in context. Findings Technology has enabled many new ways of learning. One example is Quick Response (QR) codes in which information is encoded and stored for quick access when needed. This methodology has considerable scope to enhance mobile learning because of its just-in-time characteristic. Learners can more readily find appropriate information that is presented in a concise format. However, successful implementation of QR codes requires users to have access to a capable mobile device that is equipped with an up-to-date operating system and a camera. This will aid the scanning process as will a fast and reliable internet connection. Practical implications The paper provides strategic insights and practical thinking that have influenced some of the world’s leading organizations. Originality/value The briefing saves busy executives and researchers hours of reading time by selecting only the very best, most pertinent information and presenting it in a condensed and easy-to-digest format.

Scheduling multiple servers to facilitate just-in-time part-supply in automobile assembly lines

2018 ◽  
Vol 38 (3) ◽  
pp. 347-360 ◽  
Author(s):  
Tao Peng ◽  
Binghai Zhou
Keyword(s):  
Local Search ◽  
Ant Colony Optimization ◽  
Ant Colony ◽  
Mixed Integer ◽  
Inventory Level ◽  
Just In Time ◽  
Tree Search ◽  
Assembly Lines ◽  
Content Type ◽  
Automobile Assembly

Purpose With regard to product variety and cost competition, just-in-time (JIT) part-supply has become a critical issue in automobile assembly lines (AALs). This paper aims to investigate a multiple server scheduling problem (MSSP) encountered in the JIT part-supply process of AALs. Parts are stored in boxes and allotted from the JIT-supermarket to consumptive stations with a multiple server system. The schedule is to dispatch and sequence material boxes on each server for minimizing line-side inventory levels. Design/methodology/approach A mixed integer linear programming (MILP) model is established to formulate the proposed MSSP to pave the way for CPLEX procedure. Considering the high complexity of MSSP, a hybrid ant colony optimization (HACO) approach is developed by integrating basic ant colony optimization (ACO) with local optimizers that comprise of a fast local search and a tailored breadth-first tree search method. Findings Both CPLEX and HACO approach are capable of solving small-scale instances to optimality within reasonable computation time. The proposed HACO has been well enhanced with the embedded fast local search and tailored breadth-first tree search, and it performs robustly in a statistically significant manner when applied to real-world scale instances. Originality/value No stock-outs constraints and weighted line-side inventory level are considered in this paper, and the MSSP is solved satisfactorily to facilitate an efficient JIT part-supply of the AAL. In terms of the algorithm design, a tree search-based local optimizer is embedded into ACO to combine the mechanisms of ACO and problem-specific optimization.

Part-out-based spares provisioning management

2014 ◽  
Vol 20 (1) ◽  
pp. 76-95 ◽  
Author(s):  
Jan Block ◽  
Alireza Ahmadi ◽  
Tommy Tyrberg ◽  
Peter Söderholm
Keyword(s):  
End Of Life ◽  
Minimum Cost ◽  
Cost Effective ◽  
Successful Implementation ◽  
Content Type ◽  
Management Framework ◽  
Decision Making System ◽  
Phase Out ◽  
The Military ◽  
And Storage

Purpose – The purpose of this paper is to present the prerequisites for a part-out-based spares provisioning (PBSP) programme during the phase-out of an aircraft fleet. Furthermore, associated key decision criteria are identified and a framework for the phase-out management process is presented. Design/methodology/approach – Once a decision has been taken to phase-out an aircraft fleet, a number of routines for operations, maintenance and storage are affected and new tasks and functions must be introduced before initiating the actual parting-out process. A decision-making system and a management framework is needed to manage spares planning during the end-of-life phase to ensure availability at minimum cost and to ensure a manageable risk of backorders. Findings – For PBSP programme during the phase-out of an aircraft fleet to succeed and be cost-effective, a number of linked processes, tasks and decisions are required, e.g., those included in the framework proposed in this paper (see Figure 3). A successful implementation of PBSP also requires that these processes and tasks are carried out in a timely manner and that the communications between the concerned parties are prompt, clear and direct. One experience from the studied case is that close and trustful contacts and cooperation between the operator and maintenance provider(s) will greatly facilitate the process. Originality/value – Although the PBSP method is fairly commonly applied within both the military and the civilian sector, somewhat surprisingly very literature has been published on the subject. Indeed, remarkably little has been published on any aspects of maintenance during the end-of-life period.

Modeling errors in parts supply processes for assembly lines feeding

2017 ◽  
Vol 117 (6) ◽  
pp. 1263-1294 ◽  
Author(s):  
Antonio Casimiro Caputo ◽  
Pacifico Marcello Pelagagge ◽  
Paolo Salini
Keyword(s):  
Human Error ◽  
Quantitative Model ◽  
Model Errors ◽  
Assembly Lines ◽  
Content Type ◽  
Quantitative Evidence ◽  
Corrective Measures ◽  
Quality Costs ◽  
Parts Feeding ◽  
Feeding Systems

Purpose The purpose of this paper is to develop a quantitative model to assess probability of errors and errors correction costs in parts feeding systems for assembly lines. Design/methodology/approach Event trees are adopted to model errors in the picking-handling-delivery-utilization of materials containers from the warehouse to assembly stations. Error probabilities and quality costs functions are developed to compare alternative feeding policies including kitting, line stocking and just-in-time delivery. A numerical case study is included. Findings This paper confirms with quantitative evidence the economic relevance of logistic errors (LEs) in parts feeding processes, a problem neglected in the existing literature. It also points out the most frequent or relevant error types and identifies specific corrective measures. Research limitations/implications While the model is general purpose, conclusions are specific to each applicative case and are not generalizable, and some modifications may be required to adapt it to specific industrial cases. When no experimental data are available, human error analysis should be used to estimate event probabilities based on underlying modes and causes of human error. Practical implications Production managers are given a quantitative decision tool to assess errors probability and errors correction costs in assembly lines parts feeding systems. This allows better comparing of alternative parts feeding policies and identifying corrective measures. Originality/value This is the first paper to develop quantitative models for estimating LEs and related quality cost, allowing a comparison between alternative parts feeding policies.

Expected maintenance waste reduction benefits after implementation of Just in Time (JIT) philosophy in maintenance (a statistical analysis)

2019 ◽  
Vol 25 (1) ◽  
pp. 25-40 ◽  
Author(s):  
Sandeep Phogat ◽  
Anil Kumar Gupta
Keyword(s):  
Data Interpretation ◽  
General Information ◽  
Spare Parts ◽  
Waste Reduction ◽  
Maintenance Cost ◽  
Just In Time ◽  
Content Type ◽  
Great Saving ◽  
Research Findings ◽  
Structured Questionnaire

Purpose The maintenance department of today, like many other departments, is under sustained pressure to slash costs, show outcome and support the assignment of the organization, as it is a commonsensical prospect from the business perspective. The purpose of this paper is to examine expected maintenance waste reduction benefits in the maintenance of organizations after the implementation of just-in-time (JIT) managerial philosophy. For this, a structured questionnaire was designed and sent to the 421 industries in India. Design/methodology/approach The designed questionnaire was divided into two sections A and B to assist data interpretation. The aim of the section A was to build general information of participants, type of organization, number of employees, annual turnover of the organization, etc. Section B was also a structured questionnaire developed based on a five-point Likert scale. The identified critical elements of the JIT were included in the questionnaire to identify the maintenance waste reduction benefits in the maintenance of organizations. Findings On the basis of the 133 responses, hypothesis testing was done with the help of Z-test, and it was found out that in maintenance, we can reduce a large inventory of spare parts and also shorten the excessive maintenance activities due to the implementation of JIT philosophy. All the four wastes: waste of processing; waste of rejects/rework/scrap in case of poor maintenance; waste of the transport of spares, and waste of motion, have approximately equal weightage in their reduction. Waste of waiting for spares got the last rank, which showed that there are little bit chances in the reduction of waiting for spares after the implementation of JIT philosophy in maintenance. Practical implications The implication of the research findings for maintenance of organizations is that if maintenance practitioners implement elements of JIT philosophy in maintenance then there will be a great reduction in the maintenance wastes. Originality/value This paper will be abundantly useful for the maintenance professionals, researchers and others concerned with maintenance to understand the significance of JIT philosophy implementation to get the expected reduction benefits in maintenance wastes of organizations which will be helpful in the great saving of maintenance cost and time side by side great increment in the availability of machines.

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