scholarly journals Measurement of Work-in-Process and Manufacturing Lead Time by Petri Nets Modeling and Throughput Diagram

10.5772/50288 ◽  
2012 ◽  
Author(s):  
Tiago Facchin ◽  
Miguel Afonso
Keyword(s):  
Petri Nets ◽  
Lead Time ◽  
Work In Process

scholarly journals Alternativas para aumento de produtividade em uma célula de manufatura com uso das técnicas do sistema Toyota de produção: análise através da modelagem e simulação computacional

2014 ◽  
Vol 15 (1) ◽  
Author(s):  
Peter Bent Hansen ◽  
Rodrigo Gomes Da Rocha ◽  
Fernando De Oliviera Lemos
Keyword(s):  
Lead Time ◽  
Work In Process ◽  
De Se ◽  
Time Work

As mudanças que afetaram o segmento industrial nas últimas décadas conduziram ao desenvolvimento de técnicas destinadas ao aumento de produtividade e eliminação de perdas, entre as quais o Sistema Toyota de Produção (STP). Porém, o STP pode apresentar resultados diferenciados dependendo do ambiente onde é aplicado. O objetivo desta pesquisa é analisar os potenciais resultados e melhorias de produtividade passíveis de se alcançar pela aplicação de conceitos e técnicas do Sistema Toyota de Produção em uma célula de manufatura de uma empresa metal-mecânica, através da simulação computacional. O estudo constitui uma pesquisa aplicada, qualitativa e se caracteriza como um estudo de caso. Foram realizados 3 tipos de experimentos de aplicações de técnicas do STP via simulação computacional, tendo-se constatado que os mesmos produzem efeitos diferenciados em termos de produtividade, lead time, work-in-process e ociosidade dos operadores, apesar de todos convergirem para o aumento de produtividade da célula conforme esperado, porém em diferentes graus.

scholarly journals CONWIP versus POLCA: A comparative analysis in a high-mix, low-volume (HMLV) manufacturing environment

2016 ◽  
Vol 9 (2) ◽  
pp. 432 ◽  
Author(s):  
Todd Frazee ◽  
Charles Standridge
Keyword(s):  
Discrete Event Simulation ◽  
Lead Time ◽  
Manufacturing Systems ◽  
Discrete Event ◽  
Model Verification ◽  
Manufacturing Environment ◽  
Event Simulation ◽  
Work In Process ◽  
Low Volume ◽  
Average Lead

Purpose: Few studies comparing manufacturing control systems as they relate to high-mix, low-volume applications have been reported. This paper compares two strategies, constant work in process (CONWIP) and Paired-cell Overlapping Loops of Cards with Authorization (POLCA), for controlling work in process (WIP) in such a manufacturing environment. Characteristics of each control method are explained in regards to lead time impact and thus, why one may be advantageous over the other.Design/methodology/approach: An industrial system in the Photonics industry is studied. Discrete event simulation is used as the primary tool to compare performance of CONWIP and POLCA controls for the same WIP level with respect to lead time. Model verification and validation are accomplished by comparing historic data to simulation generated data including utilizations. Both deterministic and Poisson distributed order arrivals are considered. Findings: For the system considered in this case study, including order arrival patterns, a POLCA control can outperform a CONWIP parameter in terms of average lead time for a given level of WIP. At higher levels of WIP, the performance of POLCA and CONWIP is equivalent. Practical Implications: The POLCA control helps limit WIP in specific áreas of the system where the CONWIP control only limits the overall WIP in the system. Thus, POLCA can generate acceptably low lead times at lower levels of WIP for conditions equivalent to the HMLV manufacturing systems studied.Originality/value: The study compliments and extends previous studies of  CONWIP and POLCA performance to a HMLV manufacturing environment. It demonstrates the utility of discrete event simulation in that regard. It shows that proper inventory controls in bottleneck áreas of a system can reduce average lead time.

A Simulation-Based Methodology for Lot-Size Optimization

2008 ◽  
Vol 392-394 ◽  
pp. 866-872 ◽  
Author(s):  
Y. Kou ◽  
Jian Jun Yang
Keyword(s):  
Lead Time ◽  
Object Oriented ◽  
Size Optimization ◽  
Control Points ◽  
Production Environment ◽  
Lot Size ◽  
Work In Process ◽  
Simulation Based ◽  
Product Manufacturing ◽  
Set Up

In the process of lot size optimization, various factors such as machine capability and parts assembly lead time need to be considered. Within small batch and multi-items production environment, kitting parts entering to assembly systems in time may valid shorten product manufacturing period, and reduce the quantity of work-in-process (WIP). This paper built up a mathematical model with the objective function of reducing set up costs, shortening cycle of part production and reducing WIP and with constraints of machine capabilities, part process planning and kitting requirement. An object-oriented simulation model is established to control the behavior of logistics objects to meet the target functions through rules aggregation and constraints at the control points, resulting in an optimal production result.

scholarly journals Monitoring processes through inventory and manufacturing lead time

2015 ◽  
Vol 115 (5) ◽  
pp. 951-970 ◽  
Author(s):  
Lluís Cuatrecasas-Arbós ◽  
Jordi Fortuny-Santos ◽  
Patxi Ruiz-de-Arbulo-López ◽  
Carla Vintró-Sanchez
Keyword(s):  
Lean Manufacturing ◽  
Lead Time ◽  
Process Management ◽  
Mutual Influence ◽  
Batch Processes ◽  
Batch Size ◽  
Operational Parameters ◽  
Content Type ◽  
Work In Process ◽  
Operational Variables

Purpose – Since lean manufacturing considers that “Inventory is evil”, the purpose of this paper is to find and quantify the relations between work-in-process inventory (WIP), manufacturing lead time (LT) and the operational variables they depend upon. Such relations provide guidelines and performance indicators in process management. Design/methodology/approach – The authors develop equations to analyse how, in discrete deterministic serial batch processes, WIP and LT depend on parameters like performance time (of each workstation) and batch size. The authors extend those relations to processes with different lots and the authors create a multiple-lot box score. Findings – In this paper, the relations among WIP, LT and the parameters they depend on are derived. Such relations show that when WIP increases, LT increases too, and vice versa, and the parameters they depend on. Finally, these relations provide a framework for WIP reduction and manufacturing LT reduction and agree with the empirical principles of lean manufacturing. Research limitations/implications – Quantitative results are only exact for discrete deterministic batch processes without any delays. Expected results might not be achieved in real manufacturing environments. However, qualitative results show the underlying relations amongst variables. Different expressions might be derived for other situations. Practical implications – Understanding the relations between manufacturing variables allows operations managers better design, implement and control manufacturing processes. The box score, implemented on a spreadsheet, allows testing the effect of changes in different operational parameters on the manufacturing LT, total machine wait time and total lot queue time. Originality/value – The paper presents a discussion about process performance based on the mutual influence between WIP and LT and other variables. The relation is quantified for the discrete deterministic case, complementing the models that exist in the literature. The box score allows mapping more complex processes.

scholarly journals Workload Control and Order Dispatching Rules

2021 ◽  
Author(s):  
Bruna Strapazzon do Couto ◽  
Miguel Afonso Sellitto
Keyword(s):  
Lead Time ◽  
Queuing Theory ◽  
Shop Floor ◽  
Due Date ◽  
Safety Stock ◽  
Strategic Issues ◽  
Planning And Control ◽  
Work In Process ◽  
Graphical Tool ◽  
Workload Control

The purpose of this study is to choose an order dispatching rule and measure the work-in-process and lead-time in the production process of a conveyor chain manufacturer. The main strategic issue for the manufacturer is dependability, which requires meeting deadlines and managing internal lead-times. The study integrates two techniques, workload control (WLC) and an analytical hierarchy process (AHP), respectively systems for production planning and control, and multi-criteria decision support, both widely used in handling manufacturing strategic issues. The research method is a field experiment. Supported by the AHP and according to strategic criteria, practitioners selected the early due date rule (the order with the closest due date comes first) to release 231 orders. Then, employing a methodology designed to support WLC applications, the study measured key parameters that provide information regarding the overall performance of the manufacturer, the input rate, work-in-process, lead-time, throughput performance, and the level of safety stock. Using the model and a graphical tool derived from queuing theory, the throughput diagram, the study provides evidence that, although the manufacturing process is satisfactorily balanced and achieves acceptable performance, the level of safety stock is small and should be increased to prevent starvation on the shop floor.

scholarly journals Design Process to Reduce Production Cycle Time in Product Development

2018 ◽  
Vol 7 (3) ◽  
pp. 125
Author(s):  
Mahesh Mallampati ◽  
Kolla Srivinivas ◽  
Tirumala Krishna. M
Keyword(s):  
Product Development ◽  
New Product Development ◽  
Lead Time ◽  
Resource Planning ◽  
Global Market ◽  
Theory Of Constraints ◽  
Value Stream Mapping ◽  
Process Time ◽  
Production Cycle ◽  
Work In Process

<span lang="EN-US">In today’s business climate, the old adage “time is money” has been expanded to mean that time is competitive weapon. Today customer’s demands are quick delivery and good quality at reasonable price. When entering the global market the companies encounter several difficulties, the most important one being excessive time for new product development. Thus to perform in a global market, short lead times are essential to provide customer satisfaction. Lead time in manufacturer point of view is the time elapse between placing of an order and the receipt of goods ordered. There are various components of lead time such as setup time, process time, move time and waiting time. This paper deals with review of various tools and techniques to reduce lead time. This problem can be solved by transition from sequential engineering to concurrent engineering, A survey of published works in the field of designing teams in big companies has revealed that in big companies a three-level team structure is recommended, as well as a workgroup, consisting of four basic teams. Method study techniques use to examine current way of work and develop effective method base on elimination, combining, changing and simplification of activities. Various lean tools such as Single Minute Exchange of Dies (SMED), 5S, Poka-yoke, Kanban, Just-in-time (JIT), Value Stream Mapping (VSM), Jidoka, Cellular manufacturing etc. helps in reducing lead time. Also Manufacturing Resource Planning (MRPII), Theory of Constraints (TOC) classic approaches of Production Planning and Control (PPC) are use to reduce Work in Process (WIP) and flow time.</span>

scholarly journals Penerapan Lean Manufacturing Untuk Mengidentifikasi Dan Menurunkan Waste (Studi Kasus CV Tanara Textile)

2019 ◽  
Vol 5 (1) ◽  
pp. 1-7
Author(s):  
Catur Kusbiantoro ◽  
Ellysa Nursanti
Keyword(s):  
Lean Manufacturing ◽  
Lead Time ◽  
Value Added ◽  
Value Stream Mapping ◽  
Value Stream ◽  
Work In Process ◽  
Cycle Efficiency

CV. Tanara Textile merupakan salah satu perusahaan tekstil yang termasuk dalam kelompok industri penyempurnaan kain berupa kain kaos. Pada proses produksi di perusahaan masih ditemukan beberapa waste. Penelitian ini bertujuan untuk mengidentifikasi dan menurunkan waste yang terjadi pada proses produksi maka digunakan pendekatan lean manufacturing. Metode Value Stream Mapping (VSM) digunakan untuk pemetaan aliran produksi dan aliran informasi terhadap suatu produk pada tingkat produksi total, melakukan wawancara untuk pembobotan penyebab 7 waste yang sering terjadi pada proses produksi, VALSAT untuk menganalisa pemborosan dari hasil pembobotan yang selanjutnya melakukan detailed mapping tools, serta analisis FMEA untuk mengetahui penyebab kegagalan prosesyang terjadi di lini produksi lalu menghitung nilai RPN tertinggi. Selanjutnya melakukan usulan perbaikan untuk menurunkan waste unnecessary inventory serta menganalisis perbaikan secara berkelanjutan dengan PDCA. Waste terbesar ada pada Unncessary Inventory sebesar 28,571% faktor penyebabnya adalah penumpukan bahan baku, work in process (WIP), sparepart yang tidak terpakai dan penimbunan pada finished goods Sebelum perbaikan proses produksi 16 hari 9 jam dimana Value Added 6 hari 4 jam dan Lead Time 10 hari 4 jam, setelah perbaikan proses produksi menjadi 14 hari 5 jam dimana Value Added 6 hari 4 jam dan Lead Time 8 hari 1 jam, dengan demikian dapat meningkatkan process cycle efficiency sebesar 17,19% dan menghemat lead time sebesar 2,546% dengan penurunan waste sebesar 8,31%

scholarly journals Proposta de utilização do sistema Period Batch Control para redução de lead time em uma empresa de bens de capital

Production ◽  
2010 ◽  
Vol 20 (4) ◽  
pp. 612-625 ◽  
Author(s):  
Maico Roris Severino ◽  
Muris Lage Junior ◽  
Luciano Campanini ◽  
Alyne de Andrade Guimarães ◽  
Moacir Godinho Filho ◽  
...  
Keyword(s):  
Lead Time ◽  
Work In Process ◽  
Batch Control

O objetivo do presente trabalho é apresentar uma proposta para a utilização do sistema PBC (Period Batch Control), assim como de dois pré-requisitos, a saber: mudança na política de controle da qualidade e criação de uma célula virtual, para reduzir o lead time em uma empresa de bens de capital. O método de pesquisa utilizado é o estudo de caso. Resultados previstos de tal implantação indicam que a empresa estudada poderá obter vantagens significativas com a adoção do PBC como, por exemplo, redução de 46,42% no lead time do produto estudado, diminuição de custos de WIP (Work In Process) em aproximadamente 50% e redução de 31% no tempo improdutivo. Esses resultados promissores podem ser alcançados também por empresas com características semelhantes que sigam a proposta apresentada neste artigo. Academicamente, o presente trabalho contribui para aumentar a divulgação do sistema PBC, assunto carente de pesquisas no Brasil.

Application of Lean Tool (Value Stream Mapping) in Minimisation of the Non-Value Added Waste (A Case Study of Tractor Industry)

2011 ◽  
Vol 110-116 ◽  
pp. 2062-2066 ◽  
Author(s):  
Paramdeep Singh ◽  
Harpuneet Singh
Keyword(s):  
Lean Manufacturing ◽  
Lead Time ◽  
Manufacturing System ◽  
Research Work ◽  
Value Added ◽  
Value Stream Mapping ◽  
Value Stream ◽  
Work In Process ◽  
Before And After ◽  
Traditional Manufacturing

Lean manufacturing has been proved to be an effective management philosophy for improving businesses in a competitive market by eliminating non-value added waste and improving in process operations. Value stream mapping is an important tool used to identify the opportunities for various lean techniques. The present research mainly focuses on the description of a model that is developed to contrast the “before” and “after” scenarios in detail in order to obtain the various benefits such as reduced production lead time, lower work in process inventory [1] and proper utilisation of the workforce. The current manufacturing system has been compared with the proposed pull (Kanban) system which shows the benefits of the proposed lean manufacturing system over the existing traditional manufacturing system. The present research work has been carried out at typical tractor industry which shows 50.5% reduction in total lead time in the future state value mapping of the crank case and the number of operators involved in processing of crank case has also been reduced from 22 to 18.

Sign in / Sign up

Export Citation Format

Share Document