title: UML class diagram about relationship types in project management
body: <p>I'm trying to draw an class diagram for my project management software
  describing the following. It contains the following classes:</p>
  
  <ul>
  <li><code>Project</code> - software projects</li>
  <li><code>ProjectManager</code> - he/she who manage the project</li>
  <li><code>Employee</code> - people who are engage in project work</li>
  </ul>
  
  <p>and the following relationships/associations:</p>
  
  <ol>
  <li><p>a project manager may have to manage more than one project, while a project can only be managed by one project manager</p></li>
  <li><p>a project manager can assign an employee to a project that he/she manages </p></li>
  </ol>
  
  <p>For the above associations I created this class diagram:</p>
  
  <p><a href="https://i.stack.imgur.com/8UcHt.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/8UcHt.png" alt="enter image description here"></a></p>
  
  <ul>
  <li>It's clear how to model the first association (between <code>ProjectManager</code> and <code>Project</code>)</li>
  <li>I have no idea how to model the second association<br>
  (<strong><em>how to implement that a project manager is only able to assign projects to employees that he is responsible to manage ?</em></strong>)</li>
  </ul>