Procedures are extensively employed to assist with working safely.Every organization has rules, policies, procedures, and standards by which its constituents must abide to.These three principals are the basis for policy acceptance and consistent behavior modification.
Consistency is the goal or purpose of an SOP, to carry out all operations correctly and always in the same manner.
The choice to abide must be a voluntary action by the employees to agree and to physically act in accordance with the standards of the organization.
This makes the application of standards difficult as they must be communicated to the employee base through documentation, managerial involvement, and company culture.
An existing SOP may need to just be modified and updated, or you may be in a scenario where you have to write one from scratch.
It sounds daunting, but it's really just a checklist.