SoITS aflevering 5 Thomas Loftager Nielsen Lasse Deleuran Jacob Mahler-Andersen Gruppe 1

Context diagram Subject domainConnection domain Guests Hotel Reception HBS > Hotel Reception Database Rooms

Context diagram description We have structured our context diagram as shown in figure 18.6 for information- provision function. After reviewing our stimulus/response list we found the boundary for the diagram where instances like the management has been excluded because it doesn't contribute to any goals. We have choosen to keep a high level of abstraction, but kept the right flow-arrows instead of simple lines showing that there is a connection. The database is included because the SuD attemps to manipulate the data within while the rooms provide the system with the data needed to maintain itself. The subject- and connection domain consist of the trivial resception desk employee and guests as stated in one of the first assignments. We found no significant delays or distorsions to include in the diagram.

Requirement diagram Reservation GUI HBS New booking Change booking Remove booking Rooms Database Receptionist

Requirement diagram description We have choosen a functional decomposition of our requirement level decomposition diagram because it fits the information-provision functional system of our best. We use a Von Neumann style in our diagram: The database contains data and has no functional behaviour while there are separate entities for stateless functions. The resceptionist, as the only external entity, send requests to the GUI from which there is an event flow to the functions to the functions that interact with the database. There is a reverse dataflow from the database to the receptionist through the functions and GUI to represent the response from the system. To validate our diagram we have checked that each function is handled by an entity in our diagram. The diagram is simplified so it does not contain the part where the system manages checked in guests. We also did a quick data access check where we concluded the data in the database is maintained as intended.

The context diagram together with the decomposition diagram fulfill the desired properties of the combined system because we describe all the desired properties of the system in these two diagrams. The context diagram gives an overall high-level description of the elements and the relations in the system, where the requirement diagram gives a more low-level description of the Hotel Booking System (HBS).