Consider an elevator system, such as the one in politong building in siping campus. it is composed of e elevators, side by side, in one building, serving f floors. at each floor there are buttons to call elevators, displays to show the position of elevators, and doors. inside each elevator there are buttons and displays too. each elevator is moved by one engine. all these elements are connected to a computer that controls everything. in the following you should analyze and model the elevator system. 1 (14 points) – a. define the context diagram and interfaces elevator system user electric power supply maintenance crew emergency crew emergency support actor logical interface physical interface user buttons, displays on floors and on elevators maintenance crew gui menus and windows to analyze and change state of system screen and keyboard electric power supply 220v , 20a, 3 poles emergency crew procedures to switch on / off / operate the system in case of emergency specific buttons and switches to power off / on emergency support procedure to ask intervention in case of emergency bj11 port (public telephone network) remark that an elevator system typically comprises the elevators (the cabins going up and down), all displays and buttons, the engines to move the elevator, the (computer based) controller. those components are shown in the system design diagram. it is possible to define a different context diagram (for instance with only the controller inside, and all the rest outside), but then the relative system design is different (contains only the computer and hardware software interfaces to engines, displays etc). list the requirements in tabular form id type (functional non functional) description 1 f call an elevator at floor f (request on button from user at floor f) 2 f compute mission m (include choice of what elevator to send) 3 f request elevator e to floor f (request from user inside elevator) 4 f show position of elevator e inside elevator (manage display in elevator) 5 f show position of elevator e at floor f (manage display at floor f) 6 f open doors for elevator e 7 f close doors for elevator e 8 f open doors at floor f, elevator e 9 f close doors at floor f, elevator e 10 f send mission m to elevator e 11 f send request for emergency intervention 12 f get / set status of elevator for maintenance tasks nf performance – update displays in < 1 sec business rules 1 floor doors must be closed when elevator is not at floor 2 elevator doors should be closed when elevator travels 3 missions should be defined to minimize waiting time for users define the glossary (uml class diagram) for the system