A Bus has properties of
regno and model.
regno
A BusType has properties of tno and description. A BusType may be had by many Buss. A BusType may permittedOn many Routes. A BusType may canDrive many Drivers.
A Route has properties of rno, description, start point (location) and end point (location). A Route may be permittedOned by many BusTypes. A Route may be supplieed by many Depots. A Route may be canOperateed by many Drivers.
A Driver has properties of bdno, name, salary and p c v date. A Driver may canOperate many Routes. A Driver may qualifiedOn many BusTypes.
A Depot has properties of dno, dname and daddress. A Depot may be basedAted by many Buss. A Depot may supplies many Routes.