Just need some basic ideas for it.

State transition diagram for this one.

Consider a refrigerator with two parts. (The definitions may not be fully accepted in conversation, but this is the terminology we use.) Fridge: A unit where the temperature is kept between 37 and 41 degree Fahrenheit Freezer: A unit where the temperature is kept between 0 and -9 degree Fahrenheit. Independent compressors and related components work to maintain the desired temperatures in the respective units. We will use the Fahrenheit scale for all temperatures The user may use a control to keep the temperatures of the two units at any one of the temperatures available. For example, the user may choose to keep the fridge temperature at 38 degrees and the freezer temperature at -3 degrees The outside temperature (the temperature of the room where the refrigerator is kept) may vary between 50 degrees and 110 degrees. Assume that we have the following scenario. The user sets the fridge temperature at 39 degrees and the freezer temperature at -4 degrees. Suppose those temperatures have been attained. Let the outside temperature be 70 degrees. Since the fridge and the freezer are at the desired temperatures, they are not actively cooled at the moment. Although there is insulation, the fact that the room temperature is much higher than the inside temperatures of the two units, the freezer and the fridge temperatures increase and when they become too high, the cooling units (compressor, etc.) start working again There are independent lights within the two units that go on when the respective units are opened. When a unit is opened, it is exposed to the room and the temperature rises more rapidly than it would if the door were closed Your task in the first pass is to model the refrigerator and its two units, the fridge and the freezer