Steps for implementing GIS map applications

The process for publishing a Web GIS map application is iterative. It can be quite useful to create a simple prototype application initially, then begin to play with it and learn from it. This will help you begin to exercise ArcGIS Server and learn more about how to create GIS maps, data, and geoprocessing models to publish using a server. This work will help you develop useful ideas and insight for implementing your Web application design.

Here are some useful steps to follow to implement your Web GIS application and services:

A process for creating Web GIS mapping applications

1. Identify your audience and the tasks to be performed. Specify who will use this application and what their mission is. Is it for an executive? Is it intended for use by workers in your organization? Are you targeting your application for use by the general public (for example, the citizens of a city or county)?

   Understanding who your audience is, the tasks that your GIS will support, and the audience's level of sophistication with GIS mapping will help you determine other key aspects for your GIS map application design and deployment.

2. Identify some of the key information products that the GIS map application will be used to produce. This typically starts by identifying some of the questions that your GIS map application will be used to help answer.

   GIS map applications help people address particular questions; visualize information about a situation, alternative, or scenario; and communicate these situations for better understanding. Perhaps this GIS map application will help your users complete portions of a workflow or address a series of specific questions. Articulating the tasks and questions to address helps later on in deciding what information your map will contain and what tasks and tools your users will apply when working with the GIS map. Here are some examples of the types of questions you can address with your GIS map application:

   • Where are my customers?
   • Where should I put new stores or facilities?
   • Who is impacted by this emergency? Where are the first responders? Where are the elderly who are affected? The children? How many? Where should we place evacuation centers?
   • What is the best way to respond to a power outage?
   • What are the most congested traffic areas of in the city?
   • What is the projected tax base for land parcels under this proposed plan alternative?
   • What is the environmental impact of a new development?
   • What is the air quality impact on children near major roads?
   • What happens if the water level rises one meter?

3. Pick the GIS map application you want to use. Because of the number of options available for GIS map applications, this step may seem daunting. But just as often, you may already know what your preference is for application deployment.

   Professional GIS users and editors will typically use ArcGIS Desktop. Mobile workers will use an ArcGIS Mobile application. The general public might employ a Web application or perhaps an explorer application like Google Earth or a more GIS-centric application like ArcGIS Explorer. One approach is to choose the application that you want to make work and then experiment with it to learn more about implementation and deployment with that application. Knowing what GIS tools your users will apply and on what kinds of maps and data can often help you narrow down your options.

4. Determine what the basemap is. Also, determine what the navigation and other operations are that your users will perform on the basemap. There is a series of alternative strategies you can consider for the basemap in your GIS map application. These include the following:
   • Using a map service from ArcGIS Online
   • Using a basemap service from another organization
   • Creating and serving your own basemap
   • Using Google Earth, Google Maps, or Microsoft Bing Maps as your basemap
   • Deploying your map application using a series of independent map layers
   Each choice is suitable for deployment in certain situations and to meet certain application needs. See How to build online basemaps for more information.
5. Decide what the operational layers are. These map layers are used to conduct tasks within your GIS map application. Operational layers are used to display dynamic information such as map layers that represent ever-changing sensor observations, status layers, layers used to perform editing tasks, and layers used to perform other focused tasks. Tools associated with operational layers tend to be based on the specific tasks of your target users.

   Some operational layers are derived as the result of GIS modeling and analytic operators. These often take a few properties and locations as inputs from the GIS map application, which are sent as a request to the GIS server. The GIS server then executes the model and produces a series of results. Subsequently, results are returned from the server to the GIS map applications as operational map layers. These operational layers typically require additional tools that help you visualize, analyze, summarize, graph, compare, and report on the results. See Building dynamic map layers (operational layers) for more information.

6. Determine what tools need to be used with each operational layer. There are certain operations and tasks that users need to perform with each operational layer. Maybe its a special way to render the map layer. Perhaps it is a tool used to chart and compare results.

   It's important to make a short list of the operations you'll need to support. Compare these with the out-of-the-box capabilities of your GIS map application. Build a plan to add any missing tools (for example, via custom programming or by writing a geoprocessing model and publishing it as a geoprocessing task service using ArcGIS Server).

7. Create and author the basemap using ArcMap (or ArcGlobe for a 3D map). Typically, a number of map documents are created to support GIS mapping applications on the Web—at least one for the GIS basemap (if your GIS is to be used as the source for the basemap) and additional map services for each operational layer.
8. Write geoprocessing models, publish them as ArcGIS Server tasks, and incorporate these into your GIS map. In this step, you'll build and publish the necessary geoprocessing models as ArcGIS Server tasks so that your users will be able to access these from their GIS map applications. You should also think about the software tools that the application will need for users to work with results that are derived from the geoprocessing services.

   See An overview of geoprocessing with ArcGIS Server for more information.

9. Determine how the contents for each service will be hosted or served (and who will host the service). This often involves more than establishing a series of map services to be hosted on your local GIS server.

   You'll need to consider the following types of decisions:

   • Determine whether any content needs to reside with the application (for example, mobile maps that need to be onboard the mobile appliance).
   • List all the map layer contents you will access within the GIS map application and ensure that you have a GIS service for delivering each.
   • Ensure that you compile the list of tools to be accessed from ArcGIS Server.

10. Build and test the GIS map application and GIS services. For more guidance, see Introduction to creating Web applications with Manager in the ArcGIS Server help.
11. Determine a strategy for maintaining the GIS map content, services, and application logic. For example, see Automating cache creation and updates with geoprocessing in the ArcGIS Server help.