In a machining process, there are several stages of operation involved. The sensors are used to collect the data in all the stages at the desired intervals of time of the user. Once there is a large amount of data set, finding the stages becomes complex. The stages can be identified by the Changepoint, but the identification of Changepoint is a challenge. Changepoint detection is the estimation of breakpoints at which the statistical properties of the observation change. This Changepoint gives the inference that the stage has started/ended. Pruned Exact Linear Time (PELT) is the method adopted for detecting changepoints, which is through minimizing the cost function over possible numbers and locations of changepoints.