• CONWIP
• eVSM
• Kanban
• Lean thinking
• Pull
• Syncro-MRP
• Value Stream mapping

Abstract
Nowadays, in the global race to compete in a complex and dynamic market, Lean thinking has became the main paradigm influencing, both the manufacturing and management. The lean concepts application allows companies to “work more with less”, thanks to its focalization on waste elimination and it means to replace the push logic with the pull one. In lean projects, firstly, the value stream mapping (VSM) must be applied, a easy-to-use tool to represent the “as-is” state and define the road map, in order to streamline processes. This work, according to the stage in Continental® plants, presents the lean application to an injector component manufacturing process; VSMs have been created by eVSM software, in order to propose improvements, such as the stock reduction and the Pull System implementation. As far as this point, Kanban and CONWIP systems are compared and a hybrid system pull-push is finally proposed, too.

Introduction
In the complex and dynamic current market, companies globally strive to maintain their efficiency for remaining competitive.
Nowadays, industrial world is theatre of fundamental changes that replace the traditional players of the mass production in favor of the customer: customer has to became the center of economy, the main focus is the customer satisfaction accompanied by the quality and service level.
In this context, during the last decades, several methods have been used to reduce costs and survive in global market; among these, the “Lean thinking” has established itself as a set of principles and tools to streamline processes and improve the resources exploitation. To achieve these goals, the waste elimination is needful: “waste”, referred to Japanese word “muda”, is anything that does not add value to the product, therefore the customer is unwilling to pay for; tasks to be carried out are inherent the reduction of long lead times and materials stocks and removal of reworks and defects.
One of companies that decided to follow the lean-oriented concepts, is Continental.
This work has been developed from a stage experience, lasting 6 months, at the plants of Continental Automotive Italy Spa, located in Pisa; this manufacturer is specialized in the production of electro fuel injectors, for gasoline engines.
The main scope of this paper is to describe the industrial example of the lean principles application to an injector component manufacturing process, in order to highlight the benefits deriving from this.
Firstly, general information about the Continental Corporate, a worldwide company, are given in order to contextualize Pisa plants; for these, a brief history is reported and then, product portfolio and the injector, object of the study, are presented.
The second part of the work is dedicated to the lean thinking, in particular the evolution of lean concept since its birth, the lean principles, among which the pull system that is the aim to be achieved, and the lean tools, with a section devoted to the eVSM, a specific software to create Value Stream Maps, used within this company.
As far as the operational part, the starting point is the choice of product family, suitably justified, to which to be applied the pull system. By using the eVSM tool, the final assembly line is drawn, in order to show components involved so to select one of them; the current state map of chosen component is finally built.
In this work it is possible noticed the importance of VSM technique used, for example, as an ex-post analysis method to identify the improvement actions (kaizen): kaizen proposed are discussed in the final part of this paper like, for example, the reduction of steel stocks and the pull system implementation.
However, the VSM technique also allows to realize the future state maps, representation of ideal state if the kaizen were implemented and, at the same time, thanks to the to-be state drawing, is possible to compare the results of similar methods to achieve the same aim. In fact, in the final section, the Kanban and CONWIP, two techniques to implement the pulled production, are compared and, another proposal, the Syncro-MRP, is also suggested, supporting each method with itself own results.
Actions and kaizen, proposed after the current state analysis, are supported by objective evidences of improvement in terms of stocks reduction, elimination of non-value-added activities and consequent decreasing of lead time. Most of these improvements are quantified in terms of cost savings by analyzing the as-is state and to-be situation, with the kaizen made.