ECA is a car auction company where car owners list their cars to be auctioned and sold immediately. The process of listing a car is as follows. The car owner visits a branch of ECA, located at all RTA car registration centers, and submits the car registration card to the ECA agent. The agent performs a full RTA car inspection and retrieves the results from the RTA center. Then, the agent enters the car details and the inspection results into the ECA app and launches an auction. The ECA sets the minimum sale price of the car automatically based on ECA previous auctions for a similar car. For example, if ECA sold three Land Cruiser 2015 cars, the minimum sale price will be based on ECA formula involving the price of the three cars. Customers access the ECA auction online and submit their bids until the auction is completed. Once the auction concludes, the ECA agent proceed with the car ownership transfer process and car owner payment process.
The management decided to update their car auction system, but the system was developed without proper documentation of the processes. You are the systems analyst assigned to generate the system diagrams, which will be used in later phases of the system update process.
Based on your information gathering to date, you have determined the following about the car auction system:
ECA maintains three databases, one for cars that passed the full inspection, and two for cars that did not pass the inspection. The difference between the later databases is one database lists the cars with serious problems, whereas the other lists the cars with minor problems.
The minimum auction sale price for a given car is calculated as follows. The system loads the previous auctions of cars with similar inspection type. Each price is adjusted to take care of car depreciation; that is, a car sold three years ago, its price is depreciated according to that fact. The system then takes the average of the depreciated prices.
The ECA agent pays the car owner as follows. If car has unpaid violations, ECA needs to deduct the violations, plus 30 AED from the car payment. If the car has no outstanding violations, no fees are added.
ECA has a processing fees of 200 AED, but this fee is not collected if the car age is less than 5 years.
Tasks:

1. Draw a Data Flow Diagram (DFD) for the system (only complete the context and zero diagrams).
2. Create a structured English process description for the automatic calculation of the car minimum sale price.
3. Draw a decision tree to reflect the process the payment settlement process