**1.2 Identification of causes that lead to low productivity in the manufacturing process of the M300 wheel hub**

In order to identify the leakages and causes of low productivity, the **5MQS** (methodology to identify waste related to machines, method, materials, man, management, safety and quality) [8] method was used. This was complimented with the use of an Ishikawa diagram to analyze root causes. The general findings were:


The 55% compliance level for the 5S at the production plant indicate the necessity of implementing the 5S methodology.

• **Material:** There is a large accumulation of inventory at the bottle neck of the process, there is an imbalance in the line and lack of order for placing material.

*Mass Production Processes*

Forging

Machining

**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

**Operation Machine Standard time** 

Inspection for cracks Magnaflux

Cutting raw material of wheel hubs Saw 49.5 73 Heating and forging of wheel hubs Furnace and press 50.79 71 Heat treatment: standardization Furnace 15.45 233 Cleaning Blasting machine 18.33 196

Pre-mechanized exterior of the flange Lathe-1 146.05 39 Roughing of interior diameter Lathe-2 for roughing 121 40 Broaching Broaching machine 61 59 **Final lathing of exterior Lathe-3 for finishing 212 17** Boring and countersinking long holes for stay bolts Drill 1 79 46 Threading holes Tap drill 65 56

equipment

**(seconds)**

20.94 172

**Goal (pieces per hour)**

**Table 1** shows the machines and the manufacturing process for each area of the plant.

• **Production capacity** [3, 4]**:** The average real maximum production of M300 wheel hubs was 3000 units during the last half of 2017. Taking stock of performance flaws revealed that there was no record of machine stoppages or other short-comings in the process, and no standardized time tests to identify the maximum installed capacity of the plant along with bottle necks. This implies that no corrective planning and production programming is done leading to

• **Time studies:** In order to define the initial productivity level, a time study was done to find the standard time and number of pieces produced per hour in

The initial installed capacity refers to the highest possible value given the initial standard times that are calculated. From **Table 1** it can be concluded that the bottle neck [6] is at the final lathing of the exterior with a maximum of 17 pieces an hour

finished products with their final diameter (finishing processes).

There are currently 14 operators working at the plant:

cost over-runs, delays and all kinds of waste [5].

each operation. This can also be seen in **Table 1**.

**1.1 Calculating initial installed capacity and OEE (overall equipment** 

**86**

**effectiveness)**

(bold value in **Table 1**).


#### **Table 2.**

*Results of the 5S check-list applied at the plant.*

#### **Figure 1.**

*Diagram of the 5S network at the production plant.*


**89**

*The Use of Lean Manufacturing Tools to Improve the Production of Automobile Parts*

After examining the different continuous improvement methods available, it was decided to use those associated with "lean manufacturing" to improve the production process of the M300 wheel hub. The Kaizen framework was chosen to guide all the improvements. The project was done in seven steps as follows:

• **Phase 1:** Creation of Kaizen teams [10–13]: Awareness and training on how Kaizen teams work. Training on "lean manufacturing" techniques, especially: 5S's, time loss analysis, standardized work, visual management. Training was

• **Phase 2:** Initial situation assessment of work stations, using photographic

• **Phase 3:** Definition and approval of workplan: each Kaizen team presented their assessment from phase 2 along with a proposed workplan and schedule, goals (indicators), who was responsible and necessary resources to the com-

• **Phase 4:** Development and implementation of standards: This phase consisted in documenting the operations in the manufacturing process that each Kaizen

• **Phase 5:** Standardized training and implementing improvements [14]: The learning by doing method was used and adjustments were made to optimize.

• **Phase 6:** Managing and operationalization of the system. This is the last phase in developing the implementation and is comprised of standardizing the operationality of the new system and the administration to include continuous

• **Phase 7:** Closure of Kaizen first stage projects and commitment on the part of the Kaizen teams to develop new continuous improvement projects leading to

Continuing with the use of the **5MQS**, the improvements that were achieved are

• **Machines:** Starting with balancing the load, a new distribution was set up in the plant. This was complimented by establishing Standardized Work roundtables in each work cell. This guarantees that: the documentation of standardized work, visual aids, measurement instruments, necessary tools, identification of non-conforming material, a container for personal safety gear, and good

A basic preventive maintenance plan was started with the goal of reducing

**3. Implementing improvements through the strategic use of lean** 

also done on OEE (overall equipment effectiveness).

pany management who approved the plans.

*DOI: http://dx.doi.org/10.5772/intechopen.88470*

evidence, data and analysis.

considered to be a best practice.

improvement.

the beginning of stage 2.

**manufacturing tools**

lighting to aid readings.

unforeseen machine stoppages.

described below.

**2. Materials and methods**

*The Use of Lean Manufacturing Tools to Improve the Production of Automobile Parts DOI: http://dx.doi.org/10.5772/intechopen.88470*
