As an ONAP Policy Developer, I would like to ensure the following requirements are met:

• I can choose how any pair of control loops that target a common network element will interact.  E.g., "Both control loops A & B are allowed to operate on a common network element simultaneously.", "If control loop A is operating on a network element, control loop B is prohibited for making changes until A has finished and 5 minutes have elapsed.", "If control loop A is operating on a network element, and control loop B requests to operate on that element, control loop A's operations are reverted, after which B is permitted to operate on the network element."
• I can easily specify coordination behavior using a straightforward API.
• I can insert new coordination directives during runtime. 
• Support for coordination of closed loops in which a single event received by the policy segment of either control loop may target operations on several network elements.
• All PDPs coordinate in enforcing coordination as specified.
• Scaling support.
• Correct handling of uncommon race conditions: e.g., garbage collection of coordination state when a control loop fails.
• Ability to manually override coordination logic, when necessary.

This work will be captured in this wiki: https://wiki.onap.org/display/DW/Policy+R3+Casablanca+-+Control+Loop+Coordination