Firstly, you cannot “write a PSM” …. I’m not even sure what that would be. PSM is a not a document for compliance like some environmental studies. PSM, if done correctly, is a way to run a business. If developed and implemented right, it will control the human factors that control the human error that lead to component failures and /or that combine to lead to a process safety accident. Or, if the error rates and failure rates cannot be controlled low enough, then process safety elements, such as PHA, project risk management, and MOC, will help your teams decide what further independent protection layers are needed.
Forget US OSHA PSM; it is a very poor outline of process safety. Instead start by downloading and reading free resources such as those at: www.piii.com/resources/ and www.piii.com/blog/. These describes process safety management and some of process safety engineering. Then, buy and read the best standard on process safety management, which is Risk Based Process Safety, by AIChE/CCPS. You can buy it from Amazon. This is a 1000 page overview of the topic. Then, attend training courses on the topic. One such course, which is very popular, is Course 2: Process Safety Management, by us at www.piii.com. The next course is September in Charlotte, NC. You can find the calendar of courses online. Then, you will likely need to start buying and reading the 40 or so unique textbooks on process safety engineering and process safety management; most of the best ones are from AIChE/CCPS.
Photo Credit: 123rf.com