You’ve likely heard these terms before – what do they actually mean?
Connected workflows rely on an active connection to the internet in order to accomplish anything meaningful. Drawing features, viewing attributes, capturing or editing features, and other actions cannot be accomplished while the application is disconnected.
A lost connection during an edit generally results in a loss of all entered data, and data must be re-entered when a connection is eventually re-established.
Applications that require a connected workflow are relatively rare these days, and typically consist of web applications running on a mobile or tablet browser.
Disconnected workflows do not use an internet connection at all. Data is typically loaded onto a mobile device in the office at the beginning of the work day or beginning of a project.
Everything that the user needs to do in the field is supported directly in the application (display, query, capture, edit, etc.). At the end of a data collection session, the mobile device is typically brought back to the office and captured data is copied to a desktop PC or emailed to another person for check in or further processing.
Examples of applications that only work disconnected are Trimble TerraSync and Trimble SOLO.
Occasionally Connected workflows provide the “best of both worlds.” These workflows take advantage of an active internet connection, when available, to send field edits to a server and/or retrieve any available new data. However, when connectivity is unavailable, data is cached locally and the user’s work is not interrupted. Application functionality like display, edit, query, etc. all works whether connected or disconnected. Synchronization can occur later, when an internet connection is reestablished.
Examples of applications that support occasionally connected workflows are Esri ArcPad, Esri Collector, TerraGo Edge Mobile App, Fulcrum, and Trimble TerraFlex.
So, which workflow is the best choice for you? Well, it will likely vary from project to project. Some key factors to consider are:
- Will you have a constant, reliable broadband connection in the field?
If not, you won’t be able to support a connected workflow. If you know you will have a stable connection at various times throughout the work day, consider an occasionally connected or disconnected workflow.
Taking advantage of an occasionally connected workflow can potentially save you that end of day trip back to the office.
- Will you be starting each day in the office and returning to the office anyway?
If so, the extra cost of mobile broadband data and the hardware that supports it may not be worth it. Since you’ll physically be in a place where data can be synchronized before and after each day in the field, a disconnected workflow may provide everything that you need. Keeping data in sync with other users in your organization throughout the day would be the main reason to consider a connected or occasionally connected workflow in this scenario.
- What hardware and data contracts do you have or plan to purchase?
Do you already have internal/external mobile broadband cards or mobile hot spots, along with data plans, for each field user? Do you already have ArcGIS Online user accounts for each field user or an ArcGIS Server license? Do you plan to purchase these items/services? For larger organizations, these costs may be minimal relative to the productivity gain. But for smaller organizations, connectivity from the field can be expensive. On the other hand, occasionally synchronizing over Wi-Fi at a coffee shop or other free Wi-Fi source can help support a viable occasionally connected workflow.
- Will other people need to review or edit your datasets while you are working with them in the field?
If so, you’ll need to go with a connected or occasionally connected workflow in order to keep field data in sync with the rest of your organization. A disconnected workflow will leave others in the dark while you’re out in the field and can even result in edits being overwritten due to a “last in wins” policy on check in.
These are just some thoughts to get you started as you consider moving from or enhancing your current workflows to take advantage of the “latest and greatest” capabilities available.
Have you implemented any of these workflows? What other applications are you using that I missed? Please share your thoughts and experiences with us!