Use case diagrams for the representation of users requirements for a geoinformation solution
ISBN 978-85-88783-11-9
Authors
1Silveira Camara, G.; 2Fernanda da Costa, C.; 3Robbi Sluter, C.
1UNIVERSIDADE FEDERAL DO PARANÁ Email: camaragabriele@gmail.com
2UNIVERSIDADE FEDERAL DO PARANÁ Email: camiff@gmail.com
3UNIVERSIDADE FEDERAL DO PARANÁ Email: robbisluter@gmail.com
Abstract
This paper describes some of the results of a research that aims to verify the possibility of improving the quality of a geoinformation system when it is designed in accordance with requirements engineering theory. The criteria for assessing the system quality are efficiency, effectiveness and user satisfaction. In this step of this research our goal is to define and to represent the users’ requirements for the system interaction by a UML (Unified Modeling Language) user case diagram. A user case diagram is composed by two kinds of entities: actors and use cases. An actor is anybody or anything that can interact with the system. A use case is a task that an actor needs to accomplish when using the system. In this research the context of the geoinformation system is a public institution that is responsible for proposing Municipal Master Plans for the municipalities in the state of Parana, Brazil. In Brazil, since 2001, there is a law that is called “statute of the cities” which regulates the policies for municipalities’ urban regions. One of the policies that is demanded by this law is related to Municipal Master Plans. A Municipal Master Plan is composed by a set of laws and one of them determines the street network system of the city. The system is based on a street hierarchy which defines the maximum speed, traffic flow, and connections to different geographical regions. Once the street hierarchy is established it is possible to determine in-town movement and traffic. From the characteristics of the street network we can know about the municipality policies for urban mobility and transportation. Consequently, the main users of our system are urban planners and their first task in proposing a Municipal Master Plan is the design of the street network system. The users` tasks were defined as a result of requirements elicitation and analysis, which was accomplished in accordance with requirements engineering methods. In order to understand what tasks the user has to accomplish when designing a street network system we designed some paper maps based on the elicited requirements. The main result of this step of our research when the users had to do some tasks using paper maps was to identify which geographic features the user needs to see on maps in order to develop some spatial analysis that are the basis for their decision making. Besides that result we could also to define more precisely the needed map scales. Based on these results we created a user case diagram that is divided in seven steps. Each step is related to the methodology that urban planners adopted when defining a street network system [1]. The steps of user’s methodology are: (1) knowing where the limits of the districts are, and their geographic characteristics that are related to the street network and the urban occupation; (2) characterizing the urban regions based on geographic features and the urban land use; (3) verifying which streets connect different urban regions, these are arterial streets; (4) inside those regions, verify which streets connect with different districts; (5) inside every district, verify which streets function as collectors; (6) verifying the streets’ width; (7) analyzing the relation between the street hierarchical classes and the urban land use [1].In each of these steps the actor (urban planner) identifies, describes and verifies the relationship between some geographic features. In conclusion we achieved our main goal in our research step described in this paper when we used the user case diagrams for validating the system requirements with the users. That is an important step in the design and implementation of the geoinformation system. [1] Sluter, C.R.; Vam Elazzaker, C.P.J. and Ivánová, I. (2013) Defining Standard Symbols for Street Network Maps for Urban Planning Based on User Requirements. ICC 2013 Proceedings, p.883.
Keywords
geoinformation solution; user case diagram; requirements elicitation