Latest Contributions by TomDeWitte

Helping Mappers Get it Right  By Tom DeWitte and Tom Coolidge Correctly mapping a buried pipe network is difficult. Everyone in your organization depends on the information to be “right.” The geometry must be right, the location must be right, the attributes must be right, and the connectivity and flow must be right. If any of these information components are wrong, your organization incurs inefficiencies, extra expenses, and potential damage to your pipe network. The mapper is the person within the organization typically responsible for creating and maintaining this information. Every day, they come to work and face the challenge of consistently entering a large amount of information correctly—information that the entire organization depends upon to perform its own jobs. To succeed at this challenge, mappers need software tools to allow them to enter this information consistently, accurately, and efficiently. Within ArcGIS, many configurations are available to help the mapper enter and update this information correctly the first time. Some of these capabilities are real-time data quality control, and some are validations to be checked after feature editing but before posting. Let’s look at the tools and capabilities available to help mappers create the pipe network information correctly the first time. Getting the Geometry Right Getting the Geometry right is critical to ArcGIS tracing and for hydraulic engineers who import the geometry into their modeling software, such as DNV’s Synergi Gas product. Both ArcGIS tracing and hydraulic modeling software require polylines that are not self-closing and do not have multiple vertices occupying the same coordinate location. Additionally, a polyline representing a pipe segment should never have a cutback of less than 60 degrees. Implementing rules to prevent these types of misconfigured polylines is easy within ArcGIS Pro. A pulldown listing of ready-to-use geometry rules is provided for a geodatabase administrator to select and apply to the desired polyline featureclass. With these geodatabase configurations in place, the mapper will receive real-time feedback when they attempt to create an invalid geometry. Implementing the attribute rule constraint denying polylines with a cutback of less than 60 degrees, blocks this new feature from being completed. Getting the Connectivity Right Getting the connectivity right is also critical for any use case that requires tracing or an understanding of flow direction. Common use cases requiring connectivity are:                 -Hydraulic modeling                 -Emergency isolation tracing                 -Cathodic protection management Within pipe utilities such as gas, water, and district energy, there is another aspect of connectivity that the mapper also needs to consider. That is the correct assembly of the pipe network itself. There are many combinations of connectivity that are invalid.  For example, it is not valid for a gas service line to tap directly off a gas transmission line. Nor is it considered valid for a cathodic protection rectifier to be connected to a plastic pipe segment. Metallic-only fittings, such as screws, flanges, and weldolets, should not be directly connected to plastic pipe segments. The Esri-provided data models include a rulebase that defines valid connectivity between assets. Mappers using ArcGIS Pro get rule-based snapping tips to show them the valid connection options. This real-time guidance is a display mechanism to help mappers get it right the first time. When a mapper attempts to connect two assets together incorrectly, the snapping tips will not display. For example, in this example, a steel pipe is incorrectly attempting to be connected to a plastic pipe. When the mapper correctly attempts to connect a plastic distribution pipe segment to another plastic distribution pipe segment, the snapping tip displays to indicate the valid connection. Getting the Attributes Right – Calculations Mappers are continually asked to enter an ever-increasing amount of information about the asset. Implementing attribute rule calculations into the geodatabase is a great way to automate the input of the information and improve its accuracy. Decoding barcodes is a great example of the power of automation while also improving the quality of the data. In this example, an arcade script was written to automatically populate the data fields: nominal diameter, wall thickness, material, manufacturer, manufacture date, manufacturer lot number, and material component type. That is seven data fields automatically populated from one data field. For the mapper, life is simplified by having this very detailed information auto-populated. Getting the Attributes Right – Picklists Most data fields that a mapper is asked to populate have a finite number of valid values. Fields like diameter, material, component type, and even wall thickness have a limited number of valid values. The geodatabase provides two related mechanisms to allow administrators to have ArGIS provide a picklist from which the mapper can choose. Coded-value domains, and contingent values are these two mechanisms.  Coded-value domains enable an administrator to create a pre-defined list of values from which the mapper can choose.  This eliminates misspellings, inconsistent capitalization, and inconsistent abbreviation mistakes that are common with freeform data entry. When applied to a data field, the mapper will be restricted to selecting a value from the list. There is no override option. Contingent values enhance coded-value domains with a dynamic filtering capability that is based on another data field’s value within the record. For the mapper, selecting a coded-value domain value in one data field, such as asset type = Coated Steel, will automatically filter the coded-value domain list of values in another data field, such as pipe material grade. This real-time dynamic filtering can be defined as the unique combination of values across two, three, four, or more data fields.   Getting the Attributes Right – Required Field Constraints Geodatabase attribute rule constraints can also be configured to prevent the submission of an edit unless specified conditions are met. A common example is required fields. In this example, an arcade script was written and applied as an attribute rule constraint.  This attribute rule script requires that a tee cannot be submitted unless the data fields; diameter, diameter2, wallthickness, wallthickness2 are populated. More advanced logic can be applied to have conditional required fields based on values of other data fields in the same record. With this type of logic in place, mappers will be reminded at the point of submitting the record when a required data field has not been populated. Getting the Attributes Right – Validations Not all business rule logic can be consistently and correctly applied at the record submission stage. Some business logic needs to wait until the full set of edits for a construction project or repair has been applied. This delayed application of business rules is called validations. Validation checks are initiated by the user with the Validate tool or automatically as a nightly batch process. Common pipe network examples of validations are: -verifying against the utility network rule base, - verifying that the excess flow valve is coincident to a service pipe, -verifying that the valve diameter is the same as the coincident pipe diameter. These types of multi-feature data quality checks help mappers find mistakes that would be missed with simpler business rule logic applications. Getting it Right The geospatial data created and maintained by mappers is critical to the safe and reliable operation of the pipe network. Everyone in the pipe organization, from finance to engineering to field operations, depends on the geospatial data to be correct. The mappers maintaining this enterprise-level data source need robust and multi-tiered business rules to help them enter this information correctly the first time. ArcGIS is the system to provide these capabilities and to aid the mapper in getting it right the first time. PLEASE NOTE: The postings on this site are our own and don’t necessarily represent Esri’s position, strategies, or opinions. ... View more

By Tom DeWitte and Tom Coolidge Within every pressurized pipe network, whether natural gas, hazardous liquid, water, or district energy, there are one or more pressure zones. Pressure zones are foundational to the engineering and operation of pressurized pipe networks. A formal definition defines a pressure zone as a distinct subset of the pipe network where a minimum and maximum pressure range is maintained by pressure-controlling devices. Yet, knowing this definition of a pressure zone is not the same as understanding a pressure zone. Understanding a Pressure Zone Understanding a pressure zone has differing meaning across an organization responsible for managing a pressurized pipe network. System planners require an understanding of the capacity of the pressure zone and the load from customers consuming the commodity traversing the pipe network. Hydraulic engineers need to understand the capacity, load, assets, commodity flow, and the type of customers depending on the provided service. Integrity Engineers require an understanding of the pressure zone assets and their characteristics. System control center operators must understand the standard operating pressure and the current maximum allowable operating pressure (MAOP). For many others across the organization, it means visually seeing the extent of the pressure zone. With this wide range of what it means to understand a pressure zone, how does an organization achieve this understanding? Defining the Pressure Zone The need to create an inventory of the assets that comprise a specific pressure zone is foundational to all these various aspects of understanding a pressure zone. From a software perspective, this means utilizing software that can determine a pressure zone. This determination is based on how the pipe assets are connected, knowing the location of the pressure regulating devices, and an understanding of the high side and the low side of those pressure regulating devices. With this understanding of pressure zone components, add some software logic to define commodity flow, and you can now define a pressure zone. Within ArcGIS, the capability to determine a pressure zone is called the ArcGIS Utility Network. The result of the application of this capability for pressure zones is the creation of a pressure subnetwork. Defining a pressure subnetwork within ArcGIS generates multiple items of information to aid in understanding the pressure zone. These aids are: Creating a persistent graphical representation of the pressure zone. Inserting the name of the pressure zone to each asset contained within the pressure zone. Tabulating quantities of the identified assets, such as number of meters and number of valves. Performing engineering calculations to determine MAOP for the pressure zone. This inventorying, tabulating, calculating, and visualizing provide pipe organizations with the foundation to understand the pressure zone. Understanding A Pressure Zones Capacity A common derivative of the pressure subnetwork representation of the pressure zone is the tabulation of the volume within the pressure zone. Knowing a pressure zone’s pipe volume has historically been the primary challenge in accurately determining the standard operating pressure amount of commodity within this subset of networked pipes. For an individual pipe segment, tabulating volume is an exercise in remembering the middle school geometry equation for a cylinder. That equation leverages the diameter and length of the pipe. Repeating this geometry calculation thousands of times for each distribution main and service line within the pressure zone is hard for humans. It is a simple calculation for a computer. With the volume automatically tabulated for the pressure zone, the next step is to apply the Ideal Gas Law equation and some commodity specific values to determine the mass and energy stored within the pressure zone. An arcade script within a pop-up can easily perform this calculation for both the standard operating and the maximum allowable operating pressure. Having the result of this tabulation readily available whenever a user opens a pressure zone pop-up within a web application or mobile map is a significant time saver for engineers and system control operators. Understanding A Pressure Zone’s Assets Once the ArcGIS Utility Network capability defines a pressure zone, the capability updates the name of the pressure zone in all traced assets (pipe segments, valves, fittings, customer meters, etc. This assigning of the pressure zone name to each asset, simplifies follow-on pressure zone asset queries often used in capital planning, such as: Average age of pipe Length of pipe by material Length of pipe by size Understanding a Pressure Zone’s Pressure Range Core to managing a safe and reliable pressurized pipe network is knowing the maximum pressure at which the gas utility can safely operate the pressure zone. To most industries this value is known as MAOP (Maximum Allowable Operation Pressure).  This value is asset specific and will vary across the thousands of assets comprising a single pressure zone. The pressure zone MAOP is defined by the weakest link within all the assets of the pressure zone. In software terms, this is the application of a minimum function against all the pressure zone asset’s individual MAOP value to find the lowest value. The ArcGIS Utility Network capabilities can automatically tabulate this engineering value as part of defining the pressure zone. With MAOP now automatically defined and maintained by ArcGIS, whenever a new asset is installed within the pressure zone and the asset’s individual MAOP value is defined, the software will revise the pressure zone MAOP to reflect the installation of the new asset. Combining the calculation of MAOP with the tabulation of volume for a pressure zone allows for the calculation of maximum line pack. Line packing is a natural gas industry term for increasing the mass of gas within a given pressure zone. Line packing is achieved by increasing the operating pressure. An increase cannot exceed MAOP. Control room operators use this value to understand how much additional mass can be placed within the pressure zone pipe network in anticipation of a forecasted increase in customer demand. Understanding a Pressure Zone’s Extent The ability to see a visual representation of the pressure zone is another product of the ArcGIS Utility Network defining a pressure zone. The ability to see the extent of a pressure zone is key to helping a utility’s staff answer their questions. Typical questions include: Emergency Events. Which pressure zones will be impacted by wildfires and floods? Planning: Which pressure zone provides service to the address of a potential new customer? Engineering: When planning a system modification, what is the extent of the pressure zone? Understanding a Pressure Zone’s Customer Base With the pressure zone accurately defined, geospatial analysis methods can be applied to identify and inventory the customers within a given pressure zone. As an example, a buffering of customer meters with the pressure zone name can query the USA Structures Living Atlas feature layer to tabulate valuable information such as: Number of hospitals Number of schools Number of impaired / limited mobility customers Quantity of types of customers (residential, commercial, industrial, government This provides instant clarity of the customer base being served by the pressure zone. This clarity helps emergency event coordinators, engineers, and planners. Bring it All Together Historically, the information mentioned in this article has been scattered across an organization’s many data siloes, spreadsheets, and the brains of individual employees. Leveraging ArcGIS and its ArcGIS Utility Network capability to define the pressure zone brings this information together. This aggregation of information and presenting it in a manner that is easy to understand is what turns defining a pressure zone into understanding a pressure zone. PLEASE NOTE: The postings on this site are our own and don’t necessarily represent Esri’s position, strategies, or opinions. ... View more

   Beware the Ides of March By Tom DeWitte and Tom Coolidge Beware the Ides of March. Stated in less Shakespearean form, beware of March 15th. This statement was true for Julius Caesar and is true today for many GIS and compliance professionals across the United States natural gas industry. In Roman times, March 15th was the deadline for settling debts. Today in the United States, March 15th is the deadline for submitting annual reports for gas distribution and transmission companies to the U.S. Department of Transportation (U.S. DOT) Pipeline and Hazardous Materials Safety Administration (PHMSA). The submittal of the U.S. DOT PHMSA Annual Report for Gas Distribution (Form F 7100.1-1) and its sibling, the U.S. DOT PHMSA Annual Report for Gas Transmission and Gathering Pipeline Systems (F 7100.2-1), is an exercise in data mining. If your data is well organized and attuned to the data summarization requirements of these reports, gathering the information required to complete these forms is manageable. Suppose your data is not attuned to the data query, filtering, and summarization needs of these reports' data query, filtering, and summarization needs. In that case, this annual effort is scarier than having a best friend named Brutus. Officially, PHMSA estimates that the time required to gather the data needed to complete these forms is 16 hours for Gas Distribution and 47 hours for the Gas Transmission and Gas Gathering form. This is achievable with a well-attuned geospatial dataset such as an ArcGIS data repository organized with the Utility and Pipeline Data Model (UPDM). If your data is poorly organized, this effort can take several months. What does a well-attuned geospatial dataset look like? Summarizing by Pipe Material The first indication of a data model well attuned to these reports' data summarization needs is how material is defined. Part B of the Gas Distribution report does not ask for the specific material grade of the pipe (PE2708, Grade X42, etc.). It asks for a generic categorization of material (Plastic, Coated Steel, Bare Steel, Cast Iron, etc.). Part D of the Gas Transmission and Gas Gathering report similarly asked for a generic categorization of the material instead of the specific grade. The UPDM data model explicitly defines these categorizations of material in a data field called; AssetType. This AssetType data field has a set list of values which align with the categorization material values requested in the DOT reports. A simple summarization of the assettype and cptraceability data fields will produce the data values needed for section B1 of the Gas Distribution Report. A summarization of unique combinations of assettype, cptraceability, and regulatorytype will produce the data values needed for Part D of the Gas Transmission and Gas Gathering report. These summarizations can be easily accomplished in ArcGIS with UPDM-organized data in minutes versus hours, days, and even weeks. Summarizing Transmission By SMYS Part K of the Gas Transmission and Gas Gathering Report asks for the miles of transmission pipe based on the operating pressure as a percent of specified minimum yield strength (SMYS) for a given DOT class designation. Storing engineering information about the pipe as descriptors about the pipe greatly simplifies summarizing this information for the Gas Transmission and Gas Gathering Report. When the UPDM data fields for this engineering data are populated, this tabulation can be performed. The specific data fields within the pipelineline layer of UPDM are operatingpressure, SMYS, percentSMYS, dotclass and shape_length. Similar to the mileage by material table, a summarization of the unique combinations of percentSMYS, and dotclass, then summing the total length of pipe produces the information needed to populate this table. Summarizing Leaks by Cause UPDM and its optimization of data organization to support the reporting needs of the annual DOT reports extend beyond pipes. It is also attuned to the reporting requirements of leaks. Part C of the Gas Distribution report asks for the number and severity of leaks on mains and services. Here again, the P_GasLeaks featureclass in UPDM is intentionally organized to accommodate this categorization of leak cause and severity. The data field, leakcause includes a set list of valid values, which correlates to the Cause of Leak categories of the reporting table. The data field, revisedleakclass provides the leak severity distinction, and the leakstatus data field provides the indication of the status of the leak. UPDM Alignment with DOT Reporting was no Accident The fact that UPDM is so well aligned with the reporting needs of these annual reports is not an accident of data modeling. When UPDM was originally created, these DOT reports were studied. The intent way back in 2009 was to organize this information to not only address the daily engineering and operational needs of natural gas organizations but also to simplify this required annual reporting task. In the 15 years since the original release of UPDM, the gas team at Esri has continued to monitor the evolution of these compliance reports and, when needed modify UPDM to accommodate changes in reporting. March 15th was a very bad day for Julius Caesar; it does not have to be a bad day for you.   PLEASE NOTE: The postings on this site are our own and don’t necessarily represent Esri’s position, strategies, or opinions. ... View more

By Tom DeWitte, Kevin Ruggiero, Mike Hirschheimer Part 5 of 5 Maintaining a local cache of data on a mobile device, has historically been a challenge for organizations large and small. The paper medium used for the first 150 years of the utility industry was unable to automatically update the printed copies sitting in a mobile worker’s horse wagon or truck. The first generation of mobile map viewer applications were also static. Updating these digital snapshots of data meant fully replacing the mobile device’s local cache of data. This was time consuming to the mobile worker, extremely taxing of the data server being asked to extract its contents and congested most organizations communication networks. Neither of these options are ideal for providing utility field workers with the up-to-date information they require to safely perform their jobs. What utilities desire is a mechanism that not only maintains the mobile device’s local cache of data without requiring dedicated time from the mobile worker, but also minimizes the query load against the data servers, and minimizes the impact on the communication network. What utilities desire is offline map areas. Offline Map Areas Offline Map Areas is the name Esri gives to the capability that enables the ArcGIS system to automatically transmit data changes between a mobile device and the organization’s ArcGIS data repositories for a specified geographic extent. In the previous articles of this blog series, we described the first three steps required to deploy this capability within an organization.   In this blog article we will explain the fourth and final step, deploying to the mobile device. The process of deploying to the mobile device can be divided into two parts, the initial download, and the updating of the mobile device’s data cache. How is the data initially deployed to the device When an offline map area is initially defined, a package of the requested data, layers and tables within a geographic extent are written to the portal server. This process of packaging an offline map area’s data once and storing it on the portal server addresses the issue of overwhelming the enterprise databases. By allowing mobile devices to be initially provisioned with a pre-packaged set of data, mobile workers, contractors, and mutual aid crews can quickly deploy. Each feature service included within the web map will have its extracted data written as a mobile geodatabase to a unique SQLite database file. Each image service defined within the web map will have its extracted data written to a tile package. Each vector tile package will have its extracted data written to a vector tile package. For example, a web map referencing 2 feature services, 1 hosted feature service, and 1 vector tile service will have a pre-packaged set of 3 SQLite files and 1 vector tile package sitting on the portal server waiting for download.   For a typical installation of ArcGIS Enterprise, these files will be stored in the arcgisportal install directory. NOTE: When an offline map area is created a companion scheduled process will also be created to update the portal server package. By default, this will be a weekly update. Requesting the download of an offline map area is a simple process. Within Field Maps the user will click on the download icon next to the desired offline map area. The simplicity of the download eliminates the historically time-consuming task of manually loading the packaged data onto the device. When the download is initiated, it will automatically sequence thru three steps.  The first step is to copy the portal hosted files to the mobile device. The 2nd step is to register the mobile device with the requested geodatabases. In this step each geodatabase or Data Store (hosted feature layers) will register the requesting mobile device and begin tracking the last successful synchronization date and time. This tracking of last successful synchronization date and time is how all future syncs will know which records to request to update the mobile device with changes made since the last successful sync. The 3rd step is to update the mobile device mobile geodatabases (SQLite files) with all changes made since the portal package’s last synchronization date. In this step all changes made to the enterprise data repositories (enterprise geodatabase and Portal Data Store), since the portal package was last synced, and within the defined geographic extent will be queried and downloaded to the mobile device’s existing mobile geodatabases. This ability to track the date and time of when a mobile device’s synchronization was last successfully completed for each of the local data repositories referenced by the web map is how offline map areas minimizes the network traffic required to keep current the mobile device’s data cache. With an offline map area now successfully downloaded, registered, and updated it is ready to be taken into the field for mobile worker use. Updating the Mobile Device Data Cache The mobile worker with their mobile device local cache of data, can view, and query existing data. The mobile worker can also update existing data, create new data, and delete existing data, if the web map and feature service have been configured to allow these capabilities. With this full set of editing capabilities against the local cache of data, we need to understand how those changes get back to the enterprise data repositories. When we talk about offline map area synchronization, we are talking about only receiving and sending changes to the data. Like step 3 of the initial download, the determination of what needs to be transmitted between the mobile device and the enterprise environment is based on the last successful synchronization datetime and the geographic extent of the offline map area. This datetime value is stored in both the mobile device’s mobile geodatabases, and each unique enterprise data repository providing feature data. If no changes have occurred since the last sync, there is no data to send or receive across the network. ArcGIS Field Maps provides the ability to automate this bi-directional synchronization. When auto-sync is turned on it will automatically initiate a sync when it detects a network connection to the enterprise environment. This auto-sync will occur every 15 minutes if a persistent connection to the network is maintained. For the mobile user this provides a very simple daily workflow. On a typical day the mobile worker would start in the office. While in the office the mobile worker simply opens Field Maps and selects the web map offline map area they intend to use for the day. By opening the map while connected to the office network Field Maps will automatically initiate a sync.  With the beginning of the workday sync completed, the mobile worker is ready to leave the office and head out to the field. During the day the mobile worker can view, query, and edit against their local offline map area. All edits will be stored on the device. At the conclusion of the workday, the mobile worker returns to the office. The mobile worker by simply coming into range of the office wi-fi, initiates the sync. This is due to Field Maps detecting a connection to the network and automatically initiating the sync. The mobile device never needs to leave the mobile worker’s pocket or pouch. This end of day sync will push the day’s edits to the servers and update the mobile data cache with changes posted to the enterprise environment. This automated sync frees the mobile worker from having to dedicate time to managing the local cache of data. Managing Changes to the Data Structure With the offline map areas generated and easily deployed to the mobile workforce, administrators will be asking: what happens when the structure of the data changes? The first type of data structure change to consider is the addition or removal of a layer or table to the web map. For these changes, the Update tool within the Field Maps web application is the tool to use. The update tool is very simple to use, simply click on the Update button and the Portal hosted offline map area package will be updated. When the Update tool is run it will initiate the updating of those mobile geodatabases within the Portal hosted offline map area package, which have had layers/tables added or removed. Additionally, the Update tool process will remove mobile geodatabases whose content is no longer referenced by the web map. When the schema of an existing layer or table is modified the Recreate tool is used. Examples of schema changes which require the Recreate tool are the addition or deletion of data fields, and modifications to coded value domains, range domains, and contingent value lists. Running the recreate offline area tool will delete and recreate all the mobile geodatabases contained within the portal hosted package. Managing Changes to the Mobile Devices Administering a fleet of mobile devices and the data caches stored on them can involve situations not everyone thinks about during initial planning and user acceptance testing (UAT).  For example, how does an organization deactivate a mobile device from syncing when that device has been lost or stolen. Or how do you unregister a mobile device’s offline map area when the device breaks? A different set of administration tools is needed to manage these types of situations. To manage the offline map area registration data stored within the enterprise geodatabase we need ArcGIS Pro. ArcGIS Pro provides the tools to visualize and manage all the offline map areas (feature service replicas), registered to an enterprise geodatabase. Accessing these Manage Replica tools is done via an administrative connection directly to the enterprise geodatabase. Within the Manage Replica tools is a tab for Feature Service Replicas.  This tab will present the list of all mobile device caches registered to the enterprise geodatabase. Searching by the username of the person whose device has failed or is lost, you can find the replicas to that mobile user. From this listing you can select the feature service replica which needs to be removed and unregister.  Unregistering will remove its entries from the enterprise geodatabase and prevent synchronization. Summary Unlike the book of paper maps originally stored under the bench of the horse drawn utility wagon, today’s technology enables utility organization to provide mobile users with a local cache of up-to-date information. Offline Map Areas provides the ease of use your mobile users expect from modern computing systems. These offline map areas are maintained with modern data management and communication methodologies which minimize load onto the enterprise geodatabases, and consumption of network bandwidth. All of this is done with a mature set of administrative tools, to simplify management of this enterprise system. About this Blog Series This is the fifth and final blog in our series on offline map areas. You can access our previous blogs with these links. The first blog provided and overview of offline map areas. The second blog provided details on preparing your data for offline usage. The third blog provided details and options for publishing the selected data repositories. The fourth blog provided details on how to automate the creation of the offline map areas. PLEASE NOTE: The postings on this site are our own and don’t necessarily represent Esri’s position, strategies, or opinions.                 ... View more

Taking Your Maps Offline: Publishing the Data By Tom DeWitte, Kevin Ruggiero, Mike Hirschheimer Part 3 of 5 Organizations large and small need to keep their mobile workers informed. Whether it is a blue-sky day or storms are brewing overhead, mobile workers need current information on the utility system they spend every day maintaining. This information informs the mobile worker about which conductors are energized, pipes are pressurized, and cables are live. Critical information that helps to keep the mobile worker safe and the utility system reliable. Consistently and reliably transmitting new and updated information to a utilities entire mobile workforce is not easy. The paper maps deployed for the initial 150 years of the utility industry were unable to receive incremental updates. The day after the paper maps were put into the hands of the mobile worker, the information on the map was already out-of-date. The same issue applied to early mobile map viewer applications, like ArcReader. The snapshot of information stored locally on the mobile device was unable to be incrementally updated. It too became more and more outdated with every passing day after the snapshot of information was created. These lessons learned from previous efforts to provide timely and current information to the mobile worker, tell us that a mechanism is needed to update a mobile worker’s information incrementally and consistently. In today’s mobile world, this equates to maintaining a local copy of the geospatial representation of the pipes, conductors and cables on the mobile workers phone, tablet, or laptop. The mechanism of transmitting this information to the mobile device when it is connected to a network is web services. What Are Web Services A web service is a method of communication between your mobile device and your data server. When a web service is created it is an always-on process, that is listening for mobile client applications to send requests. There are many different types of web services. Within ArcGIS Enterprise there are specialized types of web services for geocoding, geoprocessing, sharing image data, and sharing vector data.  The sharing of vector data is how feature and table records are passed between the mobile device and the centralized data repository. ArcGIS Enterprise supports multiple types of vector data web services. These include, KML, WFS, ArcGIS Feature Services and Hosted Feature Layers. ArcGIS Feature Services and Hosted Feature Layers are the only vector data sharing web services which support the synchronization of changes between the mobile device and the centralized data repository. Put another way, to keep our mobile workers informed with data changes being made by office staff and data changes being made by other mobile workers, there must be either a Feature Service or a Hosted Feature Layer to handle the communication. A feature service is how ArcGIS Enterprise Geodatabase managed data such as Utility Network data is shared to mobile devices for synchronization. A hosted feature service is how ArcGIS Portal hosted feature layer data is shared to the mobile devices for synchronization. Organizing Data with Feature Services In the example we have been describing in this blog series, the data that needs to be made available to the mobile device for local caching is coming from four different data repositories. Two of the data repositories are Enterprise Geodatabases, one data repository is the Portal’s hosted feature layers, and the fourth is an ArcGIS Online registered vector tile basemap configured for export. Each Enterprise Geodatabase will contain multiple featureclasses and tables which need to have their records synchronized to the mobile devices. A single feature service can be a grouping of 1 or more featureclasses and tables. When trying to determine how to organize your data into feature services, it is important to know that each individual feature service can only connect to one data repository.  This means that all featureclasses and table must be accessing the same enterprise geodatabase thru the same relational database connection. Publishing data for offline use has some additional constraints on the organization of content in the feature service.                   -A featureclass or table can only be referenced once.                 -Subtype group layers are not a supported layer type        Publishing a Feature Service for Syncing Creating a feature service can also be referred to as publishing the data. Publishing the data is the 2nd of the four primary steps in creating offline map areas. The “Publish the Data” step is typically accomplished with the desktop tool, ArcGIS Pro. The “Share as Web Layer” tool is the specific tool to use to publish the feature service. By default, a feature service does not support synchronization. To activate synchronization, check the box “Enable Sync” within the feature properties configuration panel. Many of the featureclasses in enterprise geodatabases have their geometries configured to support the storage of elevation (Z) and distance along a line (M). Field editors of this Z-enabled and M-enabled data may not have this information available at the time of data capture. To allow field editors to collect this information without a complete geometry definition, default values and behavior need to be defined. For the Z value check the box to turn on the “Apply default to features with Z-values”. Then set the default z-value to the desired value. For the M value check the box to turn on the “Allow geometry updates without m-value”. This will set the M value to NULL when a new feature is created.       Publishing Your Utility Network Key to keeping mobile workers safe is providing current information about their utility assets. When these assets are stored in an enterprise geodatabase and managed with the utility network capabilities, the publishing step is a matter of modifying the properties of an already published feature service. For the office mappers to create and maintain the digital connected representation of your utility assets, requires that the data be configured as branch versioned and published as a feature service. The already published utility network feature service may not be fully configured for syncing with offline map areas. To support syncing to offline map areas requires two configurations of the feature service that will need to be set. The first is to modify the already mentioned feature service properties to enable syncing. The 2nd configuration is to define the role that branch versioning will have during the synchronization process.  There are two options for branch versioning during sync: -None -Create a version for each downloaded map To know which option to set starts with an understanding of what your mobile workers will do with this utility asset data. Version Creation = None If the answer to this question is that mobile workers will only view and query the utility network data, then the default setting of “None” is the correct setting. With this configuration no additional versions are created or required to successfully sync. If you set the Version Creation option to “None” and allow your mobile workers to edit the utility assets, those edits will be posted directly to the default version. Syncing to the default version will share these edits immediately to all other office and field users. Version Creation = Version for each downloaded map This option is recommended when your mobile workers are editing the utility network managed utility assets, and those edits need to be reviewed and quality control checked prior to sharing with the rest of the organization. When this option is chosen, a branch version is created within the enterprise geodatabase when the mobile worker downloads the offline map area for the first time. All field edits will be synchronized to the created branch version. A more detailed explanation is available within the Esri online documentation. Version Creation = Create a version for each user This option is not valid for branch versioned feature services. With these two configurations set, the utility network feature service is ready to support offline map area synchronization. Publishing Your Landbase Unlike the Utility Network, a feature service may not already exist for sharing the landbase information. Office mappers may be using the ArcMap desktop application and its direct connection capability to access the landbase data stored in an enterprise geodatabase. In this example configuration the enterprise geodatabase will be using traditional versioning to track and manage changes to the landbase. Publishing the landbase feature service to support offline map area syncing requires checking feature service configuration option, Enable Sync. With sync enabled you now must decide what versioning strategy to deploy to support the mobile users. If your mobile users are not intended to create or modify the landbase features, then the correct Sync Version Creation option is: None. If you mobile users will be creating new landbase features or modifying existing landbase features then a version needs to be created to manage the flow of landbase edits. Two version management options are available for traditional versioning: “Create a version for each downloaded map” or “Create a version for each user”. A more detailed explanation of these sync version feature service options is available with the Esri online documentation. Scaling your Feature Services At the beginning of each workday there will likely be a spike in the number of mobile devices attempting to sync to the published feature services. This spike is caused by the mobile workers opening Field Maps and the offline map area enabled web map on their mobile device. This will initiate a synchronization. The capacity of a single feature service to scale to accommodate this morning spike in concurrent devices requesting to sync is defined within the pooling portion of a feature service’s properties. The pooling parameters which directly impact capacity are: Minimum number of instances per machine” and “Maximum number of instances per machine”. These parameters are adjustable after the feature service is published. The Minimum number of instances per machine value represents the base level of concurrent users that a single server can support.  As the number of requests for data increases the server will automatically start creating new additional instances.  This will continue until either the concurrent demand for data is met or the Maximum number of instances per machine is reached. If the number of concurrent user requests exceeds the maximum number of instances value, additional users will be put into a queue and must wait for an instance to become available. After the morning spike in synchronization, the number of concurrent users requesting data from the feature service will decline.  This will cause the number of instantiated instances to decline until the minimum number of instances per machine value is reached. Publishing Your Field Collected Data Hosted Feature layers provide another method of publishing data for synchronization to mobile devices. The publication process is integrated into the Hosted Feature layer initial creation process. Once a Hosted Feature layer is created it is automatically published as a feature service. Similar to an Enterprise published feature service, a hosted feature service is not sync enabled when it is initially created. Enabling sync is a task for the hosted feature layer owner, modifying the settings. Checking the box to Enable Sync is all that is required to enable syncing. Registering the Basemap to your Org The final data source to prepare for offline map areas is the basemap. For our example we will use an Esri curated basemap. Most of the Esri provided basemaps are not compatible with offline map area syncing. All ArcGIS Enterprise referenced default basemaps are NOT valid for offline map areas. Only a subset of the ArcGIS Online basemaps is valid for use within offline map areas. A listing of the 19 Esri vector basemaps for offline map areas (for export) can be viewed here. Using these ArcGIS Online basemaps in ArcGIS Enterprise requires that the basemap be registered as a layer in Enterprise, and that a valid ArcGIS Online user account is embedded within the registered vector tile layer. It is recommended that this ArcGIS Online user account is not an employee’s active account, nor should it be an account with administrative rights. This embedded user account should be a non-user account created expressly for access to the basemaps. A Persistent Listener Consistently and reliably transmitting new and updated information to a utilities entire mobile workforce requires web services. These published feature services have specific parameters which need to be configured to support syncing. Once a service is configured for syncing, it becomes a persistent listener, that is ready to respond to a mobile devices’ request for changes in data. This persistent listener is available on stormy days as well as sunny days to ensure that the utilities mobile workers have the current information they require to safely maintain a reliable utility system. About this Blog Series This is the third blog article in our series on offline map areas. In future blog articles we will continue to explain the details of how offline map areas work and the specific decisions an administrator will need to make during deployment. The first blog provided an overview of offline map areas. The second blog provided details on how to prepare the data for offline usage and synchronization. The fourth blog will provide details on the creation of offline map areas, how they are stored and managed in the portal environment. The fifth and final blog will provide details on the deployment and management of offline map areas for a large mobile workforce. PLEASE NOTE: The postings on this site are our own and don’t necessarily represent Esri’s position, strategies, or opinions. ... View more