This exercise relates to the case study 'Animal Park' which is outlined below. state any assumptions made :

a) a document flow diagram

b) a context diagram

c) a level 1 data flow diagram

d) one necessary level 2 data flow diagram.

Case - study

Animal Park

The keepers in an animal park look after the feeding of the animals. Each animal is located in a

different area of the park. Each area has its own keeper who reports to the head keeper.

The head-keeper maintains a record of the sorts of food that each animal species or type in the park

should be fed, and in what quantities. There is no distinction made between different animals of the

same species. The keepers access the information so they know what to feed each animal type. Each

animal type may be given more than one type of food, and each type of food may be fed to a number

of animal types. Each day the keepers will take out the food needed for the animals in their care and

record this on the information system. These food types can be perishable or non-perishable

according to their shelf life. For example, fresh fruit and vegetables would be perishable where tinned

produce or cereals would be considered to be non-perishable.

The ofce staff keep a track of the food supplies. They monitor which foods are running low every

two or three days and draw up a list of that which needs to be ordered. In order to help them, the

information system contains details about re-order quantities and re-order levels. Sometimes they

may need to readjust their re-order levels.

A number of suppliers are used, and their names, addresses and telephone numbers are kept in the

system. Because of the large quantities required and the difficulty of obtaining some foods at certain

times of the year, there is more than one possible supplier for each type of food. Most of the ordering

is done via the telephone, A standard order form is then created. The order form usually contains

details of more than one food type to be ordered from a particular supplier. The order also contains

details of the date of the order and what quantities are required for each food type.

When deliveries are received, the keepers check the delivery note against the goods received, amend

it if necessary and pass it on to the ofce. Here it is checked against the orders placed. It they agree,

this is recorded in the system. The office staff check the received orders against an invoice sent by the

supplier. If they agree, payment is be made. Any discrepancies are taken up with the supplier, and the

supplier's response is noted in the system. Most suppliers send an invoice each month.