title: Action Execution Specification usage in Sequence Diagram
body: <p>As I read through <code>UML Reference Manual 2004</code></p>
  
  <p>there are some examples about <code>action</code> :</p>
  
  <p>1)<code>creating and destroying object</code></p>
  
  <p>2)<code>calling an operation</code></p>
  
  <p>3)<code>sending signal to other object</code></p>
  
  <p><strong>My First question is :</strong></p>
  
  <p>Does this mean that I should use <code>action Execution Specification</code> not  <code>Behaviour Execution Specification</code> when I want to  create those types of actions?
  As you can see</p>
  
  <p><img src="https://i.stack.imgur.com/xhw9N.png" alt="enter image description here"></p>
  
  <p><strong>My Second question is :</strong></p>
  
  <p>In which cases I should use <code>Behaviour Execution Specification</code> ??</p>
  
  <p>PS: I use Papyrus for modelling the above example</p>