Cursework on Behavioral Modeling - Coursework Example

Behavioral Modeling - Behavioral Modeling Behavioral modeling is the diagrammatic representation whereby behavior of a designated system is modeled by using state nodes interconnected with transitions (Friedenthal et al 2009). There are basically two types of state machines; behavioral state machine and protocol state machine. In a class diagram, some classes transit from one state to the other over the period of their existence. In other words certain classes in a class diagram are in a dynamic state.

For example a vehicle can change its state from being “new” to “pre-owned” depending on the standing with the dealership (Dennis et al 2009). Behavioral state machine diagram is a model that reflects and show this dynamic state of any single class as it pass through its course of life and is influenced by certain events. The response to these events and actions taken by that class is also highlighted in the behavioral state machine diagram. This is used to elaborate the more complex classes and identify the events responsible for transition from one state to another.

There are different elements of a state machine diagram. State is defined as “a set of values that describes an object at a specific point in time and it represent a point in an objects life in which it satisfies some condition, performs some action, or waits for something to happen” (Dennis et al 2009). A state has a name and a universal symbol. A rectangle with rounded corner is used for the representation of state in the behavioral state diagram. However the initial and the final states are denoted by different symbols.

An initial state is the beginning of the existence of an object and a small filled in circle is used to represent it in the diagram. Final state is the end state of any object after completion of activity and is represented by dual circles like a bull’s eye (Fig 1). As per UML meta-model states can be classified as simple state, composite state, final state and pseudo state (Borger et al 2003). During the progression of a state some events cause the transitions from one state to another. Events are described by names and transitions are denoted by arrows.

Events are basically anything that changes the set values of an object. They can be interlinked or independent from each other. For example flight xxx must depart from Hong Kong before it can land in Chicago. In this example the two events are causally related. But flight xxx may arrive before or after flight xyz is unrelated and referred to as concurrent which mean they do not effect or influence each other. Every object in a system has its own properties and attributes that are important determinants of how different events will shape the changes in the system but not all attributes can significantly affect or make a difference.

For example the address of a customer will have little or no impact on offer’s state. (Dennis et al 2009). As mentioned earlier, behavioral state diagram reflect the dynamic state of any single class in a state diagram. Therefore a careful observation and understanding is required to predict the events that might change the state of an object and incorporate it in the behavioral state machine diagram. A systemic approach is required in creating that diagram. The basic initial step is to identify the states, followed by identifying the transitions.

Appropriate narration of events that are responsible for the transition of an object from one state to another is also an integral part of behavioral state machine diagram (Dennis et al 2009). Fig 1 shows the behavioral state machine diagram for a customer purchase. Fig 1: shows the behavioral state machine for a customer purchase (Source: Dennis et al 2009). In this example there are five events that changed the states of the object until it reach the final state from where no more transitions are possible.

From the beginning after the initial state, transitions to four different states occurred denoted by the rectangular boxes with rounded corners. All the events are properly explained that take part in the transtions dentoted by the arrows. Hence, we can conclude that behavioral state machine diagrams are very useful tools to understand changes in state within a complex system. It makes it easier to interpret and predict the changes that can result from an unexpected event. Moreover, behavioral state machine diagrams can be used to state the usage protocol of part of a system.

Bibliography Bo?rger, E., Gargantini, A., & Riccobene, E. (2003). Abstract state machines 2003: Advances in theory and practice : 10th international workshop, ASM 2003, Taormina, Italy, March 3-7, 2003 : proceedings. Berlin: Springer. Dennis, A., Wixom, B. H., & Roth, R. M. (2009). Systems analysis and design. Hoboken, N.J: J. Wiley. Friedenthal, S., Moore, A., & Steiner, R. (2009). A practical guide to SysML: The Systems Modeling Language. Amsterdam: Morgan Kaufmann Object Management Group/Elsevier