Lazy instantiation

This process is called eager instantiation. Another approach is not to create these state objects until the first time when they are needed, which is called lazy instantiation. Lazy instantiation is more resource efficient because the objects are not created before they are needed and are never created if they are never needed. In our situation, if we take the lazy approach, the state objects will be responsible for creating other state objects, which is against the Expert Principle (Larman, 2005). 

If we take the lazy instantiation approach, the process() in the Fragmented State class will appear as follows ... 

Lazy instantiation refers to the technique to hold loading the program until it is first requested, as it may never be needed. 

Figure 4. Sample interaction diagram for loading a fault tree using lazy instantiation mechanism. Dashed line indicate function return.

The nature of plug-in allows us to implement lazy instantiation mechanism. Since all plug-ins are independent with each other, it allows iQT platform to load and create models and services until it is first needed. 

The purpose of iQT service is to manage all registered plug-ins. iQT service is initialized when iQT platform is launched. It loads services and plugins based on lazy instantiation mechanism. 

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