System testing is basically a part of software testing and test plan should always contain specific space for this testing. To test the system as a whole, requirements and expectations should be clear and the tester needs to understand real time usage of application too.
The city of Milwaukee, Wisconsin was chosen as the location in which Happy Days was set. Tom Miller, one of the producers, grew up in Milwaukee. In addition, Milwaukee gave the show a midwest flavor that they thought would appeal to a broad-based audience.
Happy Days would appear in the top 20 several other seasons during the shows run. It finished #16 with a 21.5 during the 1974 (first season). During the 1975-76 season, it finished 11th with a 23.9 rating. Following the #1 rated season of 1976-77, it finished 2nd in 1977-78 with a 31.4 rating.