Man-hour efficiency of manual kit preparation in the materials supply to mass-customised assembly

Abstract

Addressing the materials feeding principle of kitting, commonly applied in the materials supply to mass-customised assembly, the current paper has the purpose of exploring how the man-hour efficiency of kit preparation is affected by the design and the context of the kit preparation. The study presented in the paper is based on a comprehensive methodology, comprising several steps and considering a large set of qualitative as well as quantitative data from 15 case studies. It also utilises the expertise of practitioners from the industry. The paper provides a valuable addition to the existing literature where empirical evidence is scarce. From a practical perspective, it offers support to the design of man-hour efficient kit preparation systems. The findings show that the design and the context of the kit preparation system can have a decisive, yet complex, impact on the man-hour efficiency and, thereby, on an assessment of the applicability of kitting. The paper identifies several important aspects of both design and context and indicates how these aspects are linked to the man-hour efficiency of kit preparation.

Exploring the application of machine learning to the assembly line feeding problem

“…The adoption of this policy is an effective way to reduce inventories on the shop floor and time wasted by assembly operators walking and searching for parts, compared to the case in which the unit loads received from suppliers are delivered to the stations (Limère et al 2012). On the downside, kitting gives rise to an increased material handling effort, mainly due to picking activities (Hanson and Medbo 2019). Some contributions in academic literature have introduced approaches to select the best policy for a given assembly system, starting with Bozer and McGinnis (1992).…”

Modelling time efficiency of cobot-supported kit preparation

“…While the paper has focused on the context of kit preparation, which normally is performed in dense picking areas and involves picking at frequency with small travelling distances [4], it is interesting to consider how the cobot application studied in the paper applies in other contexts. One interesting context is in warehouses and order picking.…”

“…Time expenditure on manual tasks in kit preparation depends on various aspects of kit preparation design and context [4]. In this paper, to approximate time expenditure of manual tasks, statistical distributions are used.…”

“…Kitting is here a frequently adopted materials supply principle that involves supplying assembly with components in presorted kits [1], widely seen as beneficial when there is large variety of components [2,3]. With kitting, the process by which kits are preparedthe kit preparationis typically reported as labour-intensive, and time efficiency is key for keeping running costs low [4]. Moreover, manual kit prepara-tion is prone to human errors that lead to errors in kits, which are disruptive and costly at assembly processes [5,6].…”

Cost modelling of onboard cobot-supported item sorting in a picking system

“…Their results show that kitting efficiency and accuracy can be improved by taking into account the product structure both for the information system design and for the storage assignment policy, or by applying orders batching. Also starting from empirical studies, Hanson and Medbo (2019) proposed a methodology to assess how the man-hour efficiency of kit preparation is affected by the design and the context of the kit preparation. They found that a high picking density leads to shorter kitting times, and, therefore, they suggested to take it into account during the dimensioning and the layout of the kitting area, in the design of the storage racks, and in the choice of the batch size.…”