Hi friends, in lecture six, we are going to discuss about Lean concept and tools. The learning objective of this lecture are to make you understand about the history and various concepts of lean such as value chain, local, etc. The term lean was first coined by James P. Womack and Daniel T. Jones. In their famous book named the machine that changed the world. We had discussed the historical perception of quality philosophies in lecture two. We had learned about the emergence of Japan as world leader for quality in that lecture.
During the 1990s, the Japan's Toyota Motor Company was making profits alone Which was greater than the combined profits made by three us car genes, namely, the Ford, Chrysler and GM. The car manufacturing world realize that there was something about Japanese auto manufacturers. Lots of empirical studies were conducted by various eminent management stalwarts to study about the operational excellence strategies followed by Toyota and other Japanese auto industries. The term lean was used to brand the principles and tools used by Japanese auto industries. Why it was termed lean? Because comparing to the traditional manufacturing philosophies, lean manufacturing philosophy was using less human manual Factoring effort, less manufacturing space, less engineering us to develop new product, less inventory on site, fewer defects and at the same time, greater and ever growing variety of products with high profit margin.
In order to understand the lean manufacturing philosophy, we need to have a brief understanding about other traditional manufacturing philosophies. The traditional manufacturing philosophy could be classified as craft manufacturing, mass manufacturing and the lean manufacturing. First, the craft manufacturing followed during the 1800s before the Industrial Revolution, where the individual Craftsman used to produce good for his customers Could you imagine what would be the speciality of craft manufacturing low volume of high variety products, because every individual needs were different. Then came the era of mass manufacturing after 1800 followed by the Industrial Revolution. The speciality of this manufacturing era was low variety products in high volume. After the World War Two, Japan economy was shattered.
They were struggling by the scarcity of all kinds of resources. Japan could not afford for big manufacturing setups that could produce products cheaply. The market demanded variety of products in low volumes. Japan's car manufacturer realize the necessity of paradigm shift from tradition. manufacturing methods. Lean Manufacturing concepts were then emerged as contemporary philosophies during 1970s that combines both features of craft and mass that produces high variety of batches.
In one sentence, if we want to define lean manufacturing, it is a manufacturing philosophy that shortens the time between customer order to payment by eliminating waste. Let's briefly review some of the lean concepts. The aim of Six Sigma is to reduce variation in processes. However, the aim of lean manufacturing is to reduce the wastage in the processes. value chain is one of the main concepts of lean manufacturing towards reducing the wastage in the processes. By value chain concept, it means, we are identifying the activities that adds value and activities that do not add value to the final product.
Further eliminating or reducing the non value added activities. concept of value added and non value added activities are discussed in the succeeding lecture. Similarly, the concept of flow This concept is focused on eliminating the batch and queue system of traditional manufacturing concepts and bringing the product batch to nearly one full production by full production, it means we initiate the production process only when There is a customer out of wired and connecting all the related processes in the value chain through customer pool. Five s housekeeping is the way we keep our environmental clean and organized. defining a place for each and every item such as tools, equipments, office stationery, etc. as well as ensuring a system for keeping each and every item in its defined place only Poka Yoke a or otherwise, error proofing is a system through which we ensure that mistakes are not happened even by mistakes.
Classical example could be the connector of a computer motherboard cannot have a wrong connection of ram into the motherboard because the ram could go into The motherboard in only one direction. There have been numerous studies on lean manufacturing, how will one organization go lean? Most agreed way is through achieving the 14 principles of lean concept. These 14 principles are also known as poor the model of Toyota Production System, TPS, namely philosophy that talks about the long term vision and commitment of top management. Under process, there are seven points. Some of these points have already been discussed, such as pool and flow.
The other two PS are people and partners. and problem solving prospectively another major concept that can go aligned with six sigma methodology is the concept of Theory of Constraints. Manufacturing Processes use various techniques of scheduling such as assignment theory, transportation model, linear programming, etc, in order to effectively utilize its costly and scarce resources. However, despite of using such techniques and software's, they all face the common problems like high inventory and work in process delays, backlogs, unpredictable events, etc. It is all due to some form of constraint in manufacturing in order to overcome these constraints Eliyahu goldratt Come out with a new concept in the name of Theory of Constraints to see Theory of Constraints can be better explained with the analog of the troops of marching soldiers. Imagine the scenario, a batch of 10 soldiers begin to march from some reference point.
What will happen after a few minutes in the initial phase of marching? Initially, there would be equal gap between all the soldiers isn't it? And what will happen if we watch them after a few hours of March after a few hours, and it's quite possible that the distance between the soldiers would not be the same as it were during the start of the March. This is because of the variation and the margins. speed and capacity of individual soldiers. Now, compare this scenario with any known manufacturing processes.
Similar to the soldiers, the production speed and capacity varies along with the individual machines. And it results in piling up of inventories between the process steps. Similar to Six Sigma concepts that focus on identifying and reducing the factor of variation. Theory of Constraints focus on identifying and controlling constraints resources such as bottleneck resources, any resource whose capacity is less than demand capacity constrained resources CCR any resource deviate product flow frequently to see suggest the drum buffer rope DVR methodology to handle these constraints, drum buffer rope methodology emphasize on developing schedule which is consistent with constraints keeping buffer on small inventories at critical point in system tie the product at each resource to the drumbeat. For example, imagine a process which has few sub process such as a, b c etc. And let us say E is our bottleneck process.
The DVR methodology emphasize on keeping up buffer between the bottleneck process and synchronize this process with all of the processes based on the production rate or drumbeat of this process. That's all for this lecture. objective of this lecture was to give you an overview of the lean concepts and Theory of Constraints. In the next lecture, we will learn more concepts on value added and non value added activities.