Assembling Objects (20 questions/15 minutes).It consists of 44 multiple-choice questions, each one containing an illustration of a mechanical situation. This test assesses one's ability to understand mechanical principles. Mechanical Concepts (44 questions/20 minutes).The MASS test battery is administered over approximately two hours. It consists of four tests (or sections): It may also be used when selecting candidates for power plant maintenance positions in fossil, nuclear, and hydro plants. The MASS test is similar in design, scope and administration to the POSS test. Mechanic, machinist, electrician, welder, pipefitter, steel worker, rigger.It was developed to serve as an employment selection test in the plant maintenance field. The MASS test is able to estimate the probability of a candidate's success in the following categories related to plant maintenance jobs: Have a question? Contact me at: is the MASS Test? Asif, EEI MASS Test expert at JobTestPrep.