Theory of constraints is a methodology that is used by the people to identify the constraints that are standing as a hindrance in the process of accomplishing the organizations goals besides improvising the constraint to ensure that it does not stand as an obstacle. To be precise, the limitation has to be shaped in such a way that it no longer would be a constraint. Basically, in the manufacturing industry, constraint is referred by the name called bottleneck. As per the theory of constraint (TOC), each and every process that is being carried out has a constraint. It is crucial for the organizations in their respective industry to assimilate the constraints to facilitate the whole process. Without improving the constraints, it is not possible for the organizations to improve the entire process. This is better explained with an example. If someone has handed you a match box and asked you to count. Then, to start the count you would remove the match sticks from the box and after counting you would arrange them back in the box properly. So, the constraint in this is how soon the match box is handed over to you. Did the time have an impact on your counting speed? Would you have counted the matchsticks in the box more quickly, if the match box was handed over to you a little bit before? Basically, this is how the constraint will help to boost the process. However, in this e-book we will discuss about the theory of constraints in detail. However, by reading this informative e-book, you will have a thorough understanding on the below concepts of theory of constraints.