Procedures and work instructions can take any suitable form as long as the result is effective. ISO does not specify what form these documents should take. Procedures can take the form of a narrative, a flow chart, a process map, or any other suitable form. As long as the procedure is effective, it really doesn’t matter what it looks like.
Work instructions can also take any suitable form. However, one of the best ways to document a work instruction is to use a form. Forms are particularly useful because they become records once they’re filled in.