the behavior of various tasks ( Shen, Wang, Yang, & Yeh, 2012a ). Also it shows a sequential or concurrent flow from one activity to another ( Saleh & El-Morr, 2004 ). Here, activity diagrams are used to represent functional models of the Expert Cloud at the conceptual level during the early stages of its development. In the development of the Expert Cloud many activity diagrams were designed among those job requesting action from one HR is shown in Fig. 5 as an example.
4.4. Class diagram
The class diagram shows the static structural behavior of the system, in which attributes and operations are designed for the complete system ( Vipin & Ajay, 2012 ). The class diagram includes objects and relationships between them to show the general description of the system. The classes can be related to each other in number of ways, like they can be associated, dependent, specialized or packaged. In the Fig. 6 the simplified class diagram of the Expert Cloud is shown.
In the Fig. 6 , there are 24 classes which are connect to each other with aggregation, dependency, association and inheritance relations. The most important properties of the Expert Cloud are shown by these class diagrams. For example, Quality Management and the HR management class handle and manage the activities based on the strategy and goals of organization. Because the number of classes of this diagram is high, we should reduce the number of classes for system analysis. Of course by removing each class we delete a relation between two or more class. So, we use component diagram to reduce number of classes in the following section.