**Abstract**

The competitiveness of the national and international market for automobile parts requires that delivery times, quantities and agreed upon quality standards for the ordered product are rigorously adhered to. This means that a company must use and keep up with strategies that allow for improvement while maintaining a high performance-level in its production processes. The company accepts their clients' challenge to increase the production capacity and improve levels of quality and productivity for their M300 wheel hub1 production line. The first step was to carry out a general analysis of the manufacturing process, identifying each of the activities and operations used to make the product. The critical path along with critical activities was identified and deficiencies were found in the execution of the activities along these critical paths. Next, the causes for low productivity and flaws in the production process were identified. This information was used to implement improvement proposals using "lean manufacturing" techniques with the respective results that were achieved. Conclusions and recommendations for continuous improvements in the manufacturing process are presented.

**Keywords:** wheel hub, productivity, production capacity, standard workflow, 5MQS, Kaizen, lean manufacturing

## **1. Introduction**

The improvement initiative arose when it became clear that production capacity for the front and rear M300 wheel hub needed to increase in order to meet increased demand in Ecuador and Colombia. It is a business that holds potential to deal with SOFASA and General Motors, which required high production volumes compared with the current ones.

At the same time, General Motors demands that "lean manufacturing" be applied [1, 2] as a way of both increasing productivity and ensuring high quality. The goal is to make continuous improvement processes more robust.

These strategies must be applied to the manufacture of the front and rear M300 wheel hub supplied to General Motors.

The plant is divided into two main areas: forging and machining.

<sup>1</sup> Wheel Hub. The wheel hub supports the brake drum. The wheel studs and bearing bracket are affixed to it. This arrangement transmits the torque from the drive shaft to the vehicle's wheels thus enabling movement. The part is made from steel and weights ~2.9 kg.


## **Table 1.**

*Main data related to plan operation.*

**Forge area:** The smelting process is carried out under heat. In this area, the forging process is a closed one where the material is formed by applying compression forces. The steel is shaped by pressing it between two blocks (closed matrix) while raising the temperature in industrial furnaces. The furnaces work in the same cell as the corresponding presses. A normalization process and checking for cracks also takes place in this area.

**Machining area:** here chip removal operations are preformed that result in semi-finished products through roughing (which require subsequent processes), or finished products with their final diameter (finishing processes).

**Table 1** shows the machines and the manufacturing process for each area of the plant. There are currently 14 operators working at the plant:

