Understanding distribution of responsibilities

Functionality can be distributed to logical elements by discovering what operations a block will provide. This is the same as discovering operations on classes; blocks after all are classifiers.

However, we can also depict the distribution of logical functionality to blocks depicting physical entities as well, or allocate tasks to workers. In Figure 7-16we show the allocation of a Greet interface to both a software class RestaurantGreet and a worker block Greeter.

Figure 7-16 SysML joint allocation diagram

This conveys the semantics of joint realization we discussed in Chapter 5, “Understanding distribution of responsibility” on page 79. As we refine the model, we might discover that we need a realization relationship between at least the interface and the class, if not between the interface and the block as well, as depicted previously (Figure 5-4 on page 87).

166Model Driven Systems Development with Rational Products

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IBM SG24-7368-00 manual Understanding distribution of responsibilities, SysML joint allocation diagram