Lean Supply Chains, JIT and Cellular Manufacturing-The Human Side

Article excerpt

Introduction

Lean manufacturing has been the symbol of efficiency and optimal performance since the 1980's, mainly due to its association with the automotive industry and Toyota. It has been shown to outperform the traditional production model of large batches on several occasions (Boyer, Leong, Ward, & Krajewski, 1997; Nakamura, Sakakibara, & Schroeder, 1998). Literature refers to Lean manufacturing also as "Just-in-time" (JIT), or as "cellular manufacturing" (CM). These terms are often used interchangeably, and the philosophy they describe is the same: elimination of waste, maximization of efficiency, and continuous improvement. Converting into a lean strategy involves both operational changes and, not less challenging, organizational changes.

In 1997, Power and Sohal provided a comprehensive literature review of over a hundred articles concerning the human aspects of Just-in-time, cellular manufacturing and lean production. Eight categories of previous studies were identified: corporate culture, organizational structure and the use of team, human resources issues, employee involvement, education and training, workforce flexibility and the use of kanbans, the impact of changing roles, and lastly, change management strategies (Power & Sohal, 1997). The authors identified four areas requiring further research: the impact of working in teams, role and importance of employee flexibility, the impact of education and training, and the effects of compensation. Some of these areas have been studied since, and some additional areas related to human aspects of such manufacturing strategies. The aim of this paper is to review these studies, and to identify the areas of additional required research in this field.

Manufacturing Strategies and Organizational Research

Operational changes alone do not yield expected benefits without a "bundle" which includes structural, managerial and cultural changes (Macduffie, 1995). Organizational culture remains one of the main sources of difficulty in conversion to Lean production (Johnson & Wemmerlov, 2004; Wemmerlov & Johnson, 1997). Organizational culture is also considered a major obstacle in sustaining the potential benefits of Lean production. The link between organizational culture and Lean practices is therefore an important area of study.

The importance of aligning organizational culture with operations is widely accepted. Mello and Stank (2005) provide a detailed theoretical framework for dimensions of organizational culture essential for successful supply chain management. According to their framework, supply chains consistently comprising companies that maintain trust, commitment, cooperation and top management support, will have better "supply chain orientation" and performance. Although this orientation is not directly linked to Lean production or JIT manufacturing, one of the conditions for a successful Lean strategy is consistency along the supply chain. Thus, these cultural factors are expected to be critical.

Organizational culture has also been shown to impact on other manufacturing strategies. McDermott and Stock (1999) showed different organizational cultures have different levels of managerial satisfaction from advanced manufacturing technologies (AMT). AMT is a production system that includes many lean principles (such as flexible manufacturing systems) as well as computer based technologies supporting the procurement, production and delivery of finished products.

The authors used four types of organizational cultures as described by Quinn and Spreitzer (1991): Hierarchy, Group, Rational and Developmental. The type of culture is determined according to various organizational aspects (such as leadership, organizational glue, control, rewards etc.) Group culture is characterized by participation, empowerment, teamwork and concern. Hierarchy is typically controlled, formalized and stable. …