I think the strategies are not executed in sequence as they are designed, left to right or run all children and then parent. 

Its kind of recursion, the execution occurs backwards from "Result" shape and when it reaches to the lowest point where only data is available (and no operation) its moves forward and accumulates the evaluated data and outputs as Result.

Its executed in reverse, with first component being the shape attached to "Result" component.

The execution traverses backwards from this component depending on the result and "sources" of that component,

So here the "Switch" executes first, based on the expression/outcome of Switch the execution moves to Comp1 or Comp2 , and drills further down to selected shape.

Comp1 or comp2 shape can be substrategies or any decision shape. 

Comp1 ---- |

                  |----> Switch ----> Result

Comp2 ---- |

Hi,

Strategy components are executed in single thread, and the execution follows a dependency graph as revealed by the canvas - each component is executed after all its source components are executed. In case a component has multiple source components, the order of execution is depicted in the "Source components" tab of the component's property panel.

For example in my attached scenario, S1 would resume execution after all the substrategies (SS1, SS2, SS3) are finished executing.

Hi Roveendra,

• Do we have any configuration that will be done in pega to implement the substrategy/strategy execution?

Nope, decision strategy execution is highly optimized and it is not necessary to implement the strategy execution.

Regards,
Marco.

Raveendra,

In essence, you should not really care about how sub-strategies work and execute. You should mainly care about the data flow in a strategy, how to get the business requirements implemented. 

You can find more about this in the Decision strategy execution lesson. 

Miki

p.s. As Marco explained, the internal strategy execution is highly optimized and may change from one release to another.