Clause - 8 is related to EnMS Operation and it includes requirements for Operational Planning & Control, Design and Procurement. 
The company needs to plan, apply and control the EnMS processes, concerning to its SEUs (check earlier discussed clause - 6.3), required to comply requirements and to apply the actions determined in Clause - 6.2 (discussed in earlier topics), by considering following:
 
• Developing criteria for the processes, incorporating effective operation, management and maintenance of facilities, machinery, energy systems and energy-consuming processes, where their absence can result in a significant deviation from planned energy performance. It is important to note here that the Significant deviation criteria are recognized by the company itself.• Communicating (check clause -7.4 discussed in earlier topics) the criteria to the associated individuals doing work under the influence of the company.
• Applying the control of the processes in relationship with the EnMS criteria, together with the maintenance of facilities and operations, machinery, systems and energy-consuming processes as per the developed EnMS criteria.• Maintaining documented information (check clause - 7.5) to the amount required to have the assurance that the processes have been performed as per  EnMS planning.

 
The company needs to control intended changes and assess the outcomes of unplanned changes, also the company needs to take actions so as to minimize any harmful effects, as needed.
 
The organization needs to make sure that the processes or SEUs which are outsourced but have a significant impact on SEUs (check clause - 6.3) are controlled (check clause - 8.3).