By Anthony E. Willis, Sr.; Masao Matsuoka; and Elizabeth J. Marshall
Designing a geodatabase becomes the catalyst for an enterprise system
The city of Las Vegas, Nevada, spent the past year developing an enterprise-wide geodatabase design. Though the project started as a technical geodatabase design, it actually became the catalyst for moving Las Vegas into a true enterprise GIS that is integrated with an extended business system. The city used an iterative process of learning and rethinking current business processes that resulted in more knowledgeable users who will be better able to implement enterprise GIS in the future.
This article highlights some insights and best practices the city staff developed during the project. Many of these insights are applicable to both small and large enterprises that are considering enterprise GIS.
The project's key objectives were
- Include a variety of users and domain experts in the design process.
- Create a design to accommodate data owned by the city and data imported from Clark County, Nevada, the larger region surrounding the city of Las Vegas.
- Allow distributed ownership and maintenance of the geodatabase layers.
- Allow robust integration with the city's enterprise tabular system, Hansen.
- Create a design that would facilitate a service-oriented architecture for the delivery of spatial information for viewing, workflow, and data management.
Creating the Design: Best Practices
Creating a database for the city involved a wide array of participants: a consultant team expert in geodatabase and Hansen integration, the city IT team responsible for implementing the system, and a variety of users. A number of best practices were realized in the development of the design using GeoResults Geodatabase Designer, a Web-based tool from Marshall and Associates, Inc. These best practices included change management, an iterative design process, multiple levels of access to the data, enterprise resource planning (ERP) integration, top-down implementation, multiuser participation, and management of external data.
GIS has a long and rich history in southern Nevada. Consequently, converting a coverage, tile-based system to a geodatabase structure required significant change. Managing this change was essential to the project's success. Introducing ideas early and getting constituents' feedback throughout the project were practices the city found effective.
Iterative Design Process
A well-designed geodatabase improves support of an agency's business processes. The best way to achieve this goal was iteratively developing the geodatabase design. Using this approach, participants could gain an understanding of geodatabase design requirements and the geodatabase designers could become familiar with the city's business processes.
Multiple Levels of Access
Performance for city users had to be analyzed at several levels. The city currently has a view-only geodatabase, optimized for a large number of nonediting users. A second, versioned editable geodatabase instance was created for direct access by editors. It was optimized for data management through the use of domains, relationship classes, and topology rules.
A key component to the city's design was to incorporate key fields and dependencies required for integration to Hansen. Hansen is a tabular-based ERP system used by many city departments. It was essential to design the key integration fields correctly so that ArcInfo can work like "ArcHansen" where appropriate. To do this, it is important to set up this attribute matrix between Hansen and Esri correctly and to maintain this matrix in the future. The team applied due diligence to this integration design step to ensure a system that would require minimal future modifications. Those attributes in Hansen to be linked to the geodatabase were identified in the GeoResults Geodatabase Designer. This tool allowed the export of the integration matrix. This matrix will be used by the GeoResults application and the GeoAdministrator in the future.
Since a geodatabase design has many technical aspects and seemingly a language of its own, it is important to clearly communicate with core users and managers, simply and early on, regarding what a geodatabase is and why it is being implemented. The city found that it had more success creating a high-level vision among users first, then defining the details later in the process.
Though it is clear that allowing multiple city users to provide input to the geodatabase design is important, putting this into practice can be difficult. Marshall's Web-based tool allows access by a variety of city users as well as by Marshall. This tool has an intuitive user interface for nondatabase administrators and reduced the learning curve for mastering entity-relationship diagrams. As the interactive design moved forward, users could easily change feature classes, domains, and other design aspects.
Embedded External Agency Data
The city's GIS data is based on the Street Centerline and Parcel layers that are maintained by and downloaded from Clark County as part of a southern Nevada interlocal working group for GIS. The geodatabase design needed to accommodate the importing of data from the county and allow access to this layer so city-owned layers could be built on it. Also, the city needed to retain a level of independence from the external layer in the event that the data from the county changed. Keeping track of features dependent on the street centerline and parcel layers will help manage changes to these layers in the future.
In summary, the city established a variety of best practices for geodatabase design that take into account both the technical and nontechnical components required for successful implementation. The best practices are applicable to both large and small agencies that are considering designing an enterprise geodatabase.
About the Authors
Anthony D. Willis, Sr., a senior GIS analyst with the City of Las Vegas IT-GIS team, has a bachelor's degree in economics from Jackson State University and a master's in business administration with emphasis on economic development and GIS from Millsaps College in Jackson, Mississippi. Willis has been working with GIS technology for 14 years and leads the team responsible for building a service-oriented architecture on which GIS applications and functionality will be deployed.
Masao Matsuoka has a bachelor's degree in philosophy with an emphasis on environmental ethics from the University of Idaho and a master's degree in geography from the University of Oregon. Matsuoka has more than seven years of experience working with GIS technology. His current focus is providing requirements development and implementation services to large enterprise clients.
Elizabeth J. Marshall, president of Marshall and Associates, Inc., has a bachelor's degree in applied geophysics from Michigan Technological University and a master's degree in natural resources, management, planning, and policy, with emphasis on remote sensing, from the University of Michigan. Marshall has more than 19 years of experience working with GIS technology and recently led efforts to develop Marshall's GeoResults suite of products including the company's flagship product, GeoResults Mobile.