DEA methods classify DMUs into two sets namely efficient and inefficient ones. DEA and multiple criteria DMUs are developed independently and designed for different purposes. Data Envelopment Analysis is an LPP based model and can estimate the RE of Decision Making Units with multiple outputs and inputs. Traditional Data Envelopment Analysis can trace Decision Making Units by its own weights. Moreover it splits up into inefficient and efficient DMUs. This research article explores some envelopment problems to identify extremely efficient DMUs. The ISE and OSE problems are proposed here and manifested that under constant returns to scale these problems are always feasible. © 2020.