Figure 1 The four stage network of a medical diagnostic laboratory
Figure 1 shows that the pre-test process consists of two stages: the reception unit and the sampling unit. The pre-test includes inputs like the number of active tests and the cost of consumables and outputs like the average waiting time for sampling and the average sample transfer time. The testing process consists of a stage called the test unit. The testing includes inputs like the safety cost of test unit and outputs like the number of the number of false tests. The post-test process involves a stage defined the test results unit. The post-test includes inputs like the staff wage and outputs like the number of responses of the prepared tests.
The input, intermediary, and output variables are according to Table 5:
Table 5. The notation of input variables, Intermediary variables and output variables