**2. Lean Manufacturing**

#### **2.1 Introduction**

Lean Manufacturing considered an important component of modern manufacturing units, subsequent to industrial revolutions. It removes activities/ events that don't add to the product value. **Figure 1** depicts the milestones of Lean Manufacturing. With the onset of first industrial revolution in the UK in early 1800 *Lean Manufacturing towards Green Manufacturing Practices and Its Implementation in SME's DOI: http://dx.doi.org/10.5772/intechopen.97389*


**Figure 1.**

*The road map of Lean Manufacturing post-Industrial Revolution.*

by Eli Whitney where machines were for the first time used in manufacturing. He conceived the idea of interchangeability which permitted a huge number of unskilled labours to be employed in musket manufacturing which was considered as a skilful job done by craftsman only during that time. This substantially enhanced the scale of economics in the production units. The manufacturing units intensively relied upon specific technologies till the late 1890's when one F.W. Taylor brought time study to reduce processing time. This approach measures and examines the quantum of time essential for an operator to finish the given job by means of a stopwatch thus establishing "Standard time" to complete a definite task. Subsequently, Process control chart by Frank and Lilian Gilbreth and followed by Motion Study during early 1900. The process control chart is drawn to give an actual picture of the manufacturing process and is used to take corrective and remedial actions to improve the process. The motion study is a methodology adopted to reduce unnecessary motions required to perform the task. Now both Motion study and time study are improved further and integrated and to be called method engineering. It assesses the engrossment of human beings with devices and guides human beings to effectively accomplish the given task. These innovations are the originators of waste elimination in terms of motion and idleness which are considered as forms of waste in Lean Manufacturing.

### **2.2 Lean Manufacturing practices, principles and tools**

Progress of Lean Manufacturing technique has a positive effect on the overall performance of manufacturing SMEs. This evolution in manufacturing from a traditional to lean method makes the SMEs have good productivity and in a modest manner. Lean itself is a philosophy that encapsulates productivity. Any Lean manufacturing principles are based on five principles constituting a systematic framework to effect lean implementation as shown in **Table 1** and pictorially in **Figure 2**. These principles identify non-value added activities in a production process using a variety of lean tools [8].

In short Lean Manufacturing, methodology improves productivity by creating value and reduces 7 types of common wastes encountered in a production scenario shown in **Figure 3**. In order to easily implement Lean manufacturing effectively in SMEs, a variety of Lean tools are available to support SMEs in order to implement lean. A variety of Lean tools are available as shown in **Figure 5** and their selection plays a very important role in improving the moral of SMEs in order to effectively implement the Lean Manufacturing technique. Few lean tools at an outset look to be similar in the name like process mapping or value stream mapping. Also, These Lean tools can be adopted in any SMEs situated in any country with suitable


#### **Table 1.**

*Five principle functions of Lean.*

#### **Figure 2.** *The Five Principles of Lean and Green.*

adjustments. Also, applying the wrong lean tools may cause additional resource consumption. In order to apply the correct lean tool, it is required to reclassify criteria for selecting lean Tool and map it with a particular type of waste that needs to be eliminated. So it requires a roadmap for implementing lean and it cannot be done overnight.

On successful implementation of Lean tools in SMEs resulted in enhanced Performance, Quality improvement, cycle time reduction. Lean tools enable smooth, well-organized layout yielding a high-quality product with low waste in SMEs Green factory shown in **Figure 4**. These tools have impacted significantly on manufacturing cost performance, waste reduction and improved performance [6].

*Lean Manufacturing towards Green Manufacturing Practices and Its Implementation in SME's DOI: http://dx.doi.org/10.5772/intechopen.97389*


#### **Figure 3.**

*Waste list according to Lean Manufacturing.*

**Figure 4.** *Green factory.*

#### **2.3 Systematic implementation of Lean Manufacturing**

Lean Manufacturing can improve existing productivity by eliminating nonvalue-added activity in the production chain. **Figure 5** enumerates vital lean tools used in any industry. Even though there are benefits with effective implementation of lean but still there will be few challenges left. Few lean tools incline towards similar intent of value making and they complement one another. For illustration, bottlenecking analysis, value stream mapping, continuous flow tools and Gemba analysis are used for analyzing block diagram for upgrading the value [9]. Many assortments of lean tools are available but due to poor guidance in mapping, the appropriate lean tool to beset non-value-added activity is tedious.

Normally Lean experts use a blend of different lean tools to formulate combined methods like Value stream mappings and kaizens. In the year 2015 a new model which integrate lean with the Green concept and Six Sigma using Define, Measure, Analyze, Improve, Control (DMAIC), which is parallelly implemented along with

Lean tools. To implement Lean Manufacturing the main basis is organizations culture and leadership to influence the follower's attitude and behaviour. Also, it is required to overcome inhibitors and identify critical success factors that are critical for implementing the integrated Lean Green model. Many studies discovered that human resources management is a very important critical success factor to implement successfully Lean Manufacturing in any organization. For this to happen a systematic top-down approach inside the SMEs is required [10].
