COSHH also known as Classification and Optimization-based Scheduling for Heterogeneous Hadoop systems. Multiplexing and execution of a lot of tasks happens in a common datacentre in Hadoop system. It will lead to the sharing of the Hadoop cluster among a lot of users which will lead to increase in system heterogeneity. Though in Hadoop schedulers, this issue is not given that much importance. In order to rectify that, here comes the use of COSHH, which is specially designed and implemented in order to provide scheduling at both cluster and application levels. This implementation leads to improve the completion time of job.