Analysing the impact of uncertainty reduction on WLC methods in MTO flow shops

Abstract

With more and more demanding customers, make-to-order (MTO) companies are becoming more important. Workload control (WLC) is specifically developed for MTO companies. Most previous studies have proposed solutions assuming no mismatch between planned and actual production time. However, in real situations, inaccurate estimation of processing time is a daily routine. This study focuses on processing time estimation error and evaluates performance of two different WLC order review and release (ORR) methods through simulation of a pure flow shop. Simulation results demonstrate that balancing workload is more effective than limiting workload at different error levels. However, with decrease in errors, difference in performance between limiting and balancing methods becomes wider. Further investigation shows that improving processing time estimation heavily affects the order selection process in balancing method, which is the main reason for performance improvement. Finally, aspects of Industry 4.0 are discussed in context of ORR methods in MTO flow shops.

The use of labour flexibility for output control in workload controlled flow shops: A simulation analysis

“…Due to a stronger spread of Lean Management and the consequent linearization of production flows, we will test our research question in a pure flow shop configuration (Kundu et al, 2018(Kundu et al, , 2019. This means, we consider companies whose production follows a dominant flow sequence.…”

“…A production control concept specifically developed for this kind of high variety make-to-order context is Workload Control (WLC). The concept has been shown to significantly improve production systems performances both through simulation (Kundu et al, 2018;Portioli-Staudacher & Tantardini, 2012;Thürer et al, 2012) and, on occasions, in practice. While there are several different approaches to WLC (Bergamaschi et al, 1997;Thürer et al, 2011), a major unifying principle driving WLC is input/output control (I/OC), i.e.…”

“…While I/C has received much attention in the WLC literature (Fredendall et al, 2010;Land et al, 2015;Melnyk & Ragatz, 1989;Philipoom et al, 1993;Sabuncuoglu & Karapinar, 1999;Kundu et al, 2018;, how O/C can be effectively realized has been largely neglected (Thürer et al, 2016). Only recently, more research has emerged that uses WLC theory to guide O/C decisions -in particular, when to increase capacity (Land et al, 2015;Thürer et al, 2014;.…”

Labor flexibility integration in workload control in Industry 4.0 era

“…WLC is a PPC mechanism specifically developed for a highvariety, low-volume context. The concept has been shown to significantly improve production system performance through simulation (Kundu et al 2020(Kundu et al , 2018Portioli-Staudacher et al 2020) and, on occasion, in practice.…”

“…To cope with this challenge, production planning and control (PPC) mechanisms (Małachowski and Korytkowski 2016;Reuter and Brambring 2016) play a fundamental role since PPC is intended to ensure a company's profitability by delivering goods to customers on time and in the right quantities. Workload control (WLC) is a consolidated PPC mechanism that was developed for high-variety, low-volume contexts, such as small-and medium-sized make-to-order (MTO) companies (Kundu et al 2020;Stevenson et al 2005), and it has been demonstrated to provide good margins of improvements (Kundu et al 2020(Kundu et al , 2018Portioli-Staudacher et al 2020). In addition to PPC, to cope with variability and uncertainties-for example, of demand-companies adopt different buffering strategies, such as inventory or capacity buffers (i.e., excess capacity).…”