What is the Plant Operator Selection System?
The Plant Operator Selection System (POSS) is designed to measure the foundational abilities associated with successful performance in power plant operating roles. It is used by utility companies when selecting candidates for positions in fossil-fuel, nuclear and hydroelectric power plants.
The POSS consists of four timed, multiple-choice sections:
- Reading Comprehension: 36 questions in 30 minutes. Assesses the ability to understand material similar to that found in plant operator training and safety manuals, identify relevant information and draw accurate conclusions.
- Mechanical Concepts: 44 questions in 20 minutes. Measures understanding of basic mechanical principles through illustrated problems involving equipment, forces, movement and mechanical relationships.
- Mathematical Usage: The format depends on the version administered. One version contains 18 questions in seven minutes and tests the application of supplied formulas. The other contains 46 questions in 17 minutes and covers formula conversion, algebra and word problems.
- Figural Reasoning: 20 questions in 10 minutes. Tests the ability to recognise visual patterns, identify relationships between figures and determine how picture sequences progress.
The complete assessment process normally takes approximately two hours, including instructions and administration. Candidates should work quickly and accurately because each section has a strict time limit.
POSS is used to identify candidates with the reading, mathematical, mechanical and logical-reasoning abilities needed to learn technical concepts, interpret operating and safety information, solve practical problems and work effectively in a demanding, safety-critical environment.
The assessment is not primarily intended to test previous knowledge of a particular power plant or its equipment. Instead, it evaluates the underlying aptitude associated with effective plant operations work.
Each section is scored according to the number of correct answers, with no penalty for incorrect answers or guessing. The section results are combined to produce an overall index score ranging from 0 to 15, which indicates a candidate’s predicted potential for success in plant operations. Unlike the EIAT, the published POSS format does not specify a universal 70% pass mark; employers use the combined score as part of their own selection process.
What is the best way to prepare for the POSS?
One of the most effective ways to prepare is to practise realistic questions under timed conditions. This will familiarise you with the assessment format while helping you improve your accuracy, speed and confidence.
STEP 1: Review examples of reading comprehension, mathematics, mechanical aptitude questions and Figural Reasoning questions. Learn how each type of question is presented and make sure you understand what it is asking you to do.
STEP 2: Practise questions regularly in the weeks leading up to your assessment. Short, frequent study sessions are generally more effective than attempting to learn everything immediately before the test. Concentrate additional practice on topics you find difficult.
STEP 3: Complete full sections under strict timed conditions. Work through multiple-choice questions without interruptions and practise performing mathematical calculations manually. Timed practice will help you develop a steady pace, manage pressure and avoid spending too long on a single question.
