Demystifying Pipeline Data Models
If you’re reading this, you’re likely involved with managing GIS pipeline data. If you aren’t, I recommend checking out an informative, relevant (and quite possibly more interesting) read on enhancing your GIS with integrations or connecting business processes to your GIS. If you’re still with me, strap in.
Why do we talk about data models so much in the pipeline space? From my years interacting with operators, vendors, and regulators, I believe it comes down to a handful of reasons:
- The regulatory landscape;
- The need for thorough and accurate data;
- Meeting demands of complex implementation architectures;
- Maintaining interoperability; and
- Aligning with industry standards for linear referencing.
The pipeline data model landscape can be a difficult one to navigate. Operators work with significant amounts of data and there is no shortage of models to explore.
In my last post, I introduced ArcGIS Pipeline Referencing (APR). APR is at the core of an integrated offering from Esri that incorporates linear referenced GIS (LRS) into the ArcGIS® platform. APR focuses on the “core” of the LRS, with modeling of the data on the line (events) being stored in either a Pipeline Open Data Standard Next Generation (PODS) or a Utility and Pipeline Data Model (UPDM).
This is a slight deviation from previous approaches, which has introduced some confusion. PODS and UPDM provide database models to organize your pipeline data, while APR provides a set of tools to manage and interact with it inside your GIS. Hopefully the diagram below helps explain it a bit.
Legacy data models and their impact
With the emergence of Integrated Spatial Analysis Techniques (ISAT), pipeline operators have had methods to store data about their systems and the surrounding environment since at least the early 1990s (some methods probably pre-date that). These methods have continued to develop through the work of the PODS organization and contributors to the ArcGIS Pipeline Data Model (APDM).
Each of these have offered unique benefits to the industry, but they’ve also introduced unneeded fragmentation to the landscape. As I mentioned in my previous post, APR helps simplify this by providing consolidation.
Pipeline Open Data Standard (PODS)
PODS is the data model standard for the pipeline industry. Founded in 1998, PODS was developed to extend legacy models (ISAT), and provide a baseline for software solutions in the industry. Since that time, PODS has established itself as the industry standard.
The success of PODS is rooted in the unique nature of operators and vendors coming together to meet the storage, analysis, regulatory, and reporting needs of the industry. It is important to note that PODS is more than a data model: it’s a group of individuals coming together to discuss, evaluate, and establish the data needs for the industry. The work of the PODS organization extends well beyond how to model a pipeline in a database.
PODS exists predominately in two variations: PODS Relational and PODS Spatial. Both models share a structure and format that adheres to the PODS standards, but differ in how they’re implemented. PODS Relational leverages core relational database standards, and PODS Spatial provides a native implementation for Esri Geodatabases.
Important to note: even though PODS Relational is designed as a GIS-agnostic data model (i.e. it’s not a geodatabase), most every implementation I have worked with has vendor-developed implementation methods and toolsets that integrates with Esri’s ArcGIS platform.
ArcGIS Pipeline Data Model (APDM)
APDM is the Esri pipeline data model template for pipeline assets. As with all of the models provided by Esri, APDM is a method for operators to access a structured data model, free of charge, in full support of an Esri implementation.
The template nature of APDM differs from the standards designation of PODS by allowing any portion of the base template to be altered to meet implementation requirements. This flexibility is the single biggest deviation from the standards-driven approach of PODS. Another separation between APDM and PODS is that APDM focuses on the features that make up the pipeline network itself, and is not intended to be as encompassing as the PODS models.
With the release of the UPDM, APDM has ultimately been retired.
Utility and Pipeline Data Model (UPDM)
As mentioned, UPDM has essentially replaced APDM as the recommended Esri pipeline data model. This model provides an implementation foundation for gas and hazardous liquids industries. UPDM has been designed to work with or without the APR linear referencing component of the ArcGIS platform.
Most importantly, UPDM is the first model released that allows vertically-integrated utilities (gas distribution companies that operate regulated, high-pressure lines) to consolidate database schemas, and centralize data management to a single model.
I hope this post has helped demystify the world of pipeline data models, as there is a lot to consider and it can be difficult to understand.
Next week, I will dive into what you should consider when choosing the best pipeline data model for your operation, including the limitations of different models, how APR is addressing the limitations, and the questions you should be asking yourself.
See the United Nations present at the 2017 Geocortex User Conference
The UNDSS provides safety and security services to 120,000 UN personnel in 117 countries, many of which work in challenging environments with increased risk to personal safety. Protecting UN personnel and enabling them to do their work is at the heart of what the UNDSS does.
To be successful, they must be coordinated, informed, and proactive. They maintain safety by analyzing threats, coordinating security in the field, supporting peacekeeping, collaborating with NGOs, and providing security at major events.
Andre Dehondt and Hwa Saup Lee of the UNDSS Crisis Management Information Support Section will present how their GIS helps them support this mission. Their systems provide critical information to decision makers that allows them to fulfill their duty of care obligations. Geocortex is currently used as the foundation for their Threat and Risk Assessment and Mobile Travel Advisory applications.
This is a presentation you won’t want to miss! The UNDSS does extremely important work, and they are a great example of how a GIS can help save lives and protect critical infrastructure.
We’re less than a month away from the Geocortex User Conference
This will be our first in-person conference in more than 10 years, and it’s sure to be a fun, informative, and inspiring few days! The conference takes place October 24 & 25 in Washington, DC. You can learn more about the 2017 Geocortex User Conference and register using the button below.
What is ArcGIS Pipeline Referencing and why should you be paying attention to it?
ArcGIS Pipeline Referencing (APR) is an extension to Esri’s ArcGIS platform that provides an event-based GIS, with native support for linear referenced systems (LRS), through standard Esri tools. APR allows pipeline operators to standardize data management and take advantage of established patterns for connecting this data with other business systems.
APR addresses many challenges pipeline operators have faced over the years. From consolidating multiple editing environments to providing a single solution that caters to gathering, midstream, transmission, and distribution assets, APR is enabling companies to get more from their investment in spatial data. Coupling this extension with the ArcGIS platform provides a level of integration and visibility previously unrealized in this space.
Why does it exist?
Linear referenced GIS exists across multiple industries, including roads and highways, pipelines, rail, and water/wastewater. While there are differences in how LRS is implemented within these industries, the core principles are the same: provide linear features representing the location of the asset to the Earth (the centerline); provide a standard method to reference features on the line (the linear referencing); and locate appurtenances to the line (the events).
Through the years, proprietary implementations of LRS systems have been built across many verticals. This has resulted in a complex and fragmented approach managing linear referenced data in a GIS. APR provides consolidation to this landscape, and lays the foundation for next-generation solutions.
What are the benefits to operators?
Operators stand to be the biggest benefactors of Esri providing a native pipeline referencing solution.
Standardization: With the history of divergent data model implementations in the pipeline space, operators are limited to software that supports their underlying LRS. APR is disrupting the status quo, and establishing a new baseline, ultimately allowing you to select the most effective solution for your needs, without the restriction of compatibility to your data model implementation.
Data Governance: The tight coupling of GIS and linear referencing benefits those relying on high-quality, accurate data. With the rise in GIS, and Esri driving the adoption, many GIS technicians and analysts are already knowledgeable in how to manage spatial data with Esri technology. Standardizing on APR provides operators with access to a broader range of technical staff that are capable of managing LRS data.
Consolidation: With APR, multiple linear referenced systems can be supported in the same model. Many operators manage assets across a large supply chain. Long-haul transmission lines have established patterns relying on engineering stationing, while those overseeing gathering and distribution assets tend to forgo true engineering stationing in lieu of routes and measures. Before APR, this meant implementing multiple data models, bringing with it varied methods for managing the data. Now you can consolidate: one system, one model, and one set of editors can manage all assets with the same tools.
What is UPDM (Utility and Pipeline Data Model) and how does it relate to APR?
UPDM is an accompanying data model to APR with a focus on unifying the implementation of vertically-focused operators. While UPDM provides an effective data repository, it is not the only data model compatible with APR. For example, the PODS Association is building the Next Generation model in compliance with APR.
The question then becomes, what data model should you choose for your implementation? I will be following up this post with a deep dive into the many data models that are available, and hopefully I can help you make better sense of these options.
Why are we engaged in this conversation?
Latitude Geographics provides solutions to gathering, midstream, transmission, and distribution clients around the world. In the past year, we’ve seen a sharp rise in the number of operators implementing and embracing APR. Geocortex has been 100% compatible with every implementation we’ve worked on, providing immediate value for clients leveraging PODS and UPDM.
With the release of powerful linear referenced toolsets, Geocortex can further your success with APR. Please reach out to email@example.com for more information.
Integrate key business systems to enhance your GIS
One of the most powerful capabilities of a GIS is the ability to integrate your mapping applications with 3rd party business systems and data sources. Integrating with key business systems extends the reach and capabilities of your applications, and ensures you and your team remain efficient and effortlessly informed.
So, why should you integrate your business systems with your GIS?
Added spatial awareness
Everything is somewhere, and there are patterns in data that can only be seen when looking at it on a map. Whether you need to view important asset data, or see key business intelligence data for a geographic area, the added element of spatial context takes your data to the next level.
Streamline data access
By centralizing access to important data in your mapping applications, you’re able to break down departmental siloes and improve data flow. Many organizations have important data that is difficult to access because it’s managed by another department. By integrating everything into a centralized application, data flows between systems and departments seamlessly.
The City of Brooklyn Park has realized the benefits of an integrated approach. Historically, City staff were limited to the databases and systems in their department. By integrating their assessment, licensing, land management, permitting, and police records into one internal mapping application, City staff can now access the data they need with just a few clicks.
We’ve also seen customers across other industries benefit significantly by integrating 3rd party business systems with their GIS. For example, we have helped oil and gas pipeline operators streamline their asset integrity programs. By integrating all the required data – which lives across multiple systems – into their Geocortex applications, many have been able to reduce overhead, simplify the audit process, and protect themselves from inevitable technology change.
Leave your data where it is
In most cases, you don’t even need to replicate, move or remodel your existing data to integrate it with your GIS. Geocortex Essentials offers varying levels of integration that allow you to leave your data where it lives, work with it directly on the map, and have it update the 3rd party system dynamically. It makes it simple to gain added spatial awareness and improve data flow between departments and systems.
What kinds of systems can you integrate with Geocortex?
The flexibility and extensibility of Geocortex allows you to integrate virtually any 3rd party business system or data source you’re currently using. Geocortex customers have integrated with ERP, asset and land management, document management, business intelligence, and CRM systems.
Whatever your business need is, chances are high that Geocortex can help you solve it. With a wide array of integration methods – from simple hyperlinking to custom API integrations – there is almost no limit to what you can achieve with Geocortex Essentials integrations.
Get in touch with us to learn how Geocortex can integrate with the system you’re using.
Vancouver Police Department and Geocortex: using machine learning to prevent crimes before they happen
Last week, the Vancouver Police Department (VPD) released their findings from a 6-month program they undertook with us in 2016 to pilot Geocortex Crime Forecasting, a state-of-the-art machine learning system that helps predict when and where crimes may occur.
The goal of VPD’s pilot program was to prevent break-ins and property crime throughout metro Vancouver, which typically spikes during the summer months when many people are away on vacation or leaving doors and windows open to beat the heat.
VPD focused on areas south of Broadway where residential break-ins are the most common. Special Constable Ryan Prox reported that their program reduced property crime by as much as 27% in some areas (compared to the past 4 years).
Geocortex Crime Forecasting turns simple, historic point crime data into powerful, actionable crime predictions. Predictions are quite precise; the system forecasts within a 100 m X 100 m (300’ X 300’) block, with a 2-hour time window, to determine where and when a particular type of crime might occur. By reviewing what took place in the field against predictions made for the same day, Vancouver’s Chief of Police said the system predicted with up to 80% accuracy.
With their successful pilot program complete, VPD has rolled out Geocortex Crime Forecasting to the entire police department: the first in Canada to adopt a “predictive policing” system.
The completion of the program also means that we will continue our investment in Geocortex Crime Forecasting and are excited to share it with other organizations this year!
To learn more about VPD’s program, check out the articles below:
If you want to learn more about Geocortex Crime Forecasting, we’d be happy to chat! You can contact us here.
Geocortex at the 2017 Esri User Conference
The Esri User Conference is right around the corner, taking place July 10-14 in beautiful San Diego, California. The Esri UC is our biggest event each year, and this is a particularly special year for Latitude Geographics, as we’ve launched one of our most noteworthy products in years – perhaps in the history of our company: Geocortex Workflow.
Geocortex Workflow 5 builds upon our extremely popular Geocortex Essentials workflow capabilities, and is offered as a standalone product. Geocortex Workflow 5 provides many new benefits, including: an overhauled design experience that makes building and maintaining workflows even more intuitive; the ability to run workflows in an offline environment (if using Geocortex viewers); and richer, more dynamic forms.
And for the first time in the history of Geocortex, you don’t just use our technology alongside Esri; you can leverage the power of Geocortex inside your Esri apps. Workflows authored with Geocortex Workflow 5 can run inside Esri’s Web AppBuilder for ArcGIS as a custom widget that you can acquire via the ArcGIS Marketplace.
Be among the first to explore and try out our next-generation workflow technology at one of our demo stations; we think you’ll be blown away. We’ll also be hosting a related fun activity at our booth (301) for the creative builder in everyone.
There will be many opportunities to see Geocortex Workflow – along with other exciting product enhancements -- in action during your time in San Diego:
- We’ll be in booth #301 all week! Team members from Sales, Partners, Support, Products and more will be available to chat with new and existing Geocortex customers. We will have dedicated pods for you to explore different Geocortex capabilities.
- Our annual Geocortex Technology Update will be taking place on Tuesday, July 11 from 10:30-11:30 AM in room 12 of the San Diego Convention Center. Join us to learn about key product developments, our product roadmap, and discuss our strategy with Esri’s modern technology.
- We have two dedicated Geocortex demos that will be happening in our booth. These fast-paced, hands-on demonstrations highlight the latest developments in Geocortex technology. Join as at booth #301 on Tuesday, July 11 or Wednesday, July 12 at 5:00 PM.
See you in San Diego!
When is it time to break up with a business process?
Far too often, organizations find themselves tied to inefficient, labor-intensive processes. Whether your end-users are stuck completing mindless and repetitive tasks, or they’re collecting data on paper (only to have to enter it in an archaic system in the office), it can make for a frustrating experience.
With advancements in technology, and GIS in particular, there is no reason to continue following manual, inefficient processes. There are several signs that a business process is just isn’t right for you anymore – see if any of them sound familiar.
End-users are experiencing difficulty
While this may be the most obvious sign that a process isn’t working, it’s often overlooked. When processes are complex or manual in nature, you’ll generally see end-users having difficulty completing their tasks and continually requiring assistance from the GIS department
This can slow down your workforce and bog you down with requests for assistance. One way to improve in this area is by simplifying the end-user experience; providing users with guided interactions makes for a much more pleasing experience and improves end-user success
You’re experiencing data integrity issues
Data integrity is an ongoing challenge in many organizations, and depending on the type of data being used, errors can have significant consequences. In many cases, poor data comes from using paper-based processes that are prone to transcription errors, or from not setting the proper parameters on the data being entered into an application.
At their core, GIS systems are about improving decision making. If your team doesn’t have proper information, they are not making properly informed decisions.
The best way to avoid this is to provide dedicated interfaces for data collection. Most technology will allow you to present only the data you require your field workers to collect, as well as set rules against the data being entered, to ensure it enters the system correctly. It’s unlikely that you’ll be able to completely avoid data errors, but following best practices can reduce them significantly.
Your users are spending a lot of time searching for information across disparate systems
Most organizations house important business data across several different systems; there are financial systems, asset management systems, document management systems, business intelligence systems, and many more.
If these systems are not properly integrated, it can become difficult for your end-users to track down all the information they need. It can also waste time and money if your users need to jump between systems to find information.
This pain can be alleviated with proper integrations between systems. Try making all the necessary data – regardless of which system it lives in – available in the application being used to manage a process.
For example, if your end-users need to complete fire inspections on buildings, don’t make them jump to a separate zoning system to collect information about a particular building. Instead, consider integrating the zoning system within the inspection application, and automatically present the necessary zoning info at a stage in the process that makes sense.
You’re struggling to organize and present important information to other departments and stakeholders
One of the most common, and valuable, use-cases of a GIS is conveying information to people so they can make informed decisions. If you find that your users are spending many hours collecting and compiling information into reports, it may be time to revisit the process.
Besides the obvious repetitive, inefficient nature of manually compiling reports, it takes your users away from high-value activities. Labor is expensive and you want to ensure you’re getting the most out of the investments in your team… they’ll be happier doing more fulfilling work, too!
It all comes back to decision making – if people don’t have the information they need, when they need it, and in an easy-to-interpret format, they won’t be making properly informed decisions.
When building out processes, it’s important to start with the end in mind. Consider GIS technology that allows you to auto-generate reports in different templates. Start with a vision for the report you want in mind, then tailor data collection activities based on your goals.
So, it’s time to break up - what do you do now?
If your organization is experiencing any of the challenges described above, chances are it’s time to break up with your business process(es). But that’s a big decision to make, so what do you do next?
A good start is to shadow the people responsible for completing a particular process (if it’s not you). If you’re in the office supporting a process for a different department, you may not get a full sense of everything that’s involved. It’s good to get in the trenches with your staff and really get an understanding of what it is they have to do to complete their work.
You can also try drawing your workflow out on paper, from end to end. By thinking critically about the entire flow of a process you’re able to identify areas that are ripe for improvement. We often get so tied up in the day-to-day demands of our jobs that we miss tasks that are repetitive or unnecessary. There may be steps that can be automated with the right technology, or removed entirely. Until you see the full picture, it’s difficult to determine where to adjust.
Work Smarter with Geocortex Essentials 4.7
We’re pleased to share that Geocortex Essentials 4.7 – alongside Geocortex Viewer for HTML5 2.8 and Geocortex Mobile App Framework (GMAF) 2.2 – are now available for download in the Geocortex Support Center.
Packed with tons of new features, these releases help customers improve communication, stay organized and take advantage of enhanced visualization options.
Solving Communication Challenges Spatially with Geocortex Collaboration
Communication is an ongoing – and often the most identified – challenge in many organizations, particularly when working with distributed workforces and/or field workers. In some industries, such as public safety, being able to communicate effectively is critical and can save lives and protect critical infrastructure.
Available out-of-the-box with Geocortex Viewer for HTML5 2.8, Geocortex Collaboration is a set of map-based collaboration tools aimed at streamlining how people interact through their GIS. Users can share messages, pictures and mark-up about the map in real-time, directly in your Geocortex Viewer for HTML5 applications.
You can also review how Geocortex Collaboration conversations unfolded with time slider playback. You don’t just see the result; you see how you got there so you can learn from successes and failures.
A good use case for time slider playback is emergency operations center (EOC) practice exercises; many EOCs simulate emergencies periodically to help them prepare for the real thing. By using Geocortex Collaboration for these exercises, the EOC can review how the emergency response unfolded and identify areas that are ripe for improvement. Strong emergency responses can mean the difference between life and death, so EOCs are always looking for ways to improve their responses.
The Power of Groups
Returned results are now grouped by layer, keeping everything organized and allowing you to perform additional actions on each discrete collection of results.
GIS is all about conveying information to people to help them make decisions, and we feel that these improvements to results will help you present information to your users in a way that’s intuitive and easy to interpret.
Feature Highlighting Enhancements
You can now see the extent of your selected features and easily associate individual features with your results list through improved feature highlighting and push-pin interactions. This has been one of the most sought after features in recent months, and we’re excited to deliver it with Geocortex Viewer for HTML5 2.8!
While these are some of the more prominent additions, the releases include a wide array of powerful new features. To learn about everything that’s included, or to download the new versions, please visit the product release page.
Haven’t upgraded to ArcGIS 10.5 yet? We recommend timing these upgrades together, and our ArcGIS Implementation Services team is here to help get you there!
You have a GIS. Have you connected your business processes to it?
Historically, GIS has been a system of record for many organizations, and the ability to complete any meaningful analysis lived within the GIS department. Mapping software has recently become more accessible and easy to use, and we’ve seen GIS evolve into a system of engagement and insight.
Did you know you can take your GIS even further, and use it to streamline many of your key (and often annoyingly manual) business processes?
Simplify end-user experiences with automated, repeatable tasks
Many of your end-users’ common interactions with your applications can be automated and significantly simplified. Common tasks that can be automated include:
- Data collection: Paper-based data collection -- particularly for users in the field – is still a common process for many organizations; modern GIS tools allow data to be collected seamlessly through easy-to-configure forms. Providing fields for only the information you need simplifies the experience and improves data quality.
- Visual analysis: There are many examples of visual analysis that, if not automated, would be incredibly laborious and difficult for a user to complete. For example, if a water utility needs to shut down a valve, they can quickly run an analysis inside their mapping application that shows them all the water supply sources that the shutdown will affect. To complete this manually would take many hours, and becomes increasingly costly for everyone involved.
- Reporting: When work is complete, there’s often a need to compile all the necessary information into a report; this can happen manually (and usually involves some combination of photocopying and scanning). This can be simplified with web mapping software: by pre-determining report templates, you can automatically compile the required data into a summary report.
Take charge and guide your end-users
Your end-users don’t need a set of complex GIS tools; they only want to see what is required to complete the task at hand. Automating repeatable tasks is one way to simplify the experience for your users, but there are additional steps you can take to improve your business processes.
- Guided interactions: Walking your users through the processes they need to complete increases the likelihood of success, and can reduce frustration. Only show them what they need, when they need it. A great example of guided interactions is walking the public through permit applications. Many local governments offer mapping applications where residents can submit applications online, and by guiding the public through the process, you ensure that you get the right information and that the user understands what is required of them.
- Dedicated interfaces: Offer your end-users dedicated, task-based interfaces; it reduces clutter and allows them to complete their jobs more efficiently.
- Pre-populate key fields: If your users are collecting data through the application, don’t make them complete fields that you’re able to pre-populate automatically. Fields such as who’s running the task, or what time it is, can be populated based on information that already lives in the application.
Validate data intelligently
Data integrity is an ongoing challenge for many organizations, and fixing poor data can eat up precious time. Luckily, there are approaches you can use to ensure quality data.
- Real-time validation: If your users are entering data into the application, notify them instantly if the data is incorrect. Being allowed to enter incorrect data throughout a form – only to have to go back and fix it later – can make for a frustrating experience. For example, a field worker may be completing a water meter install: if they enter the model number of the meter into the application, they can be automatically notified if it’s the wrong meter, or if there’s a duplicate meter number already in use. It saves them from installing the meter, only to find out later that it needs to be replaced.
- Rules-based validation: If you need data to be displayed in a specific format, building formatting requirements at the outset will save you – and your end-user – needless frustration. Rules-based validation allows you to provide instant feedback if a user tries to enter data in an incorrect format. An example of this that we’re all used to is password requirements. How many times have you tried to create a password for a new system, and are prompted that the password requires a capital letter, a number, and a special character? That’s rules-based validation.
Spreading the word in your organization
You can greatly improve the experience for your end-users and increase adoption of your mapping applications. For many, GIS is a foreign concept, but with a few simple tactics you can put powerful tools in the hands of your employees that are simple and intuitive to use.
Now that you know what it means to streamline business processes with GIS, it’s up to you to share this knowledge in your organization.
Why should anyone else care? At the end of the day, it all comes down to efficiency gains, consistency, and ROI. If your organization is following paper-based processes or battling with data integrity, it’s costing you time and money. By automating repeatable tasks and taking steps to ensure the correct data is collected, we’ve seen organizations save hundreds of thousands of dollars each year in operating costs.
Bay Area Rapid Transit: Improving Efficiency and Simplifying Critical Business Processes
Bay Area Rapid Transit (BART) is a public transportation system serving four counties in the San Francisco Bay Area; their rapid transit system operates 46 stations across 112 miles of track, with an estimated average ridership in 2016 of 433,000 trips per weekday, and close to 129 million trips for the entire year.
For more than four decades, BART has been an efficient and reliable way for San Francisco’s Bay Area Residents to commute: what began as a futuristic dream in 1972 has grown to be a vital part of the regional culture and economy.
A major challenge BART faced was how to manage the ongoing need for track maintenance and repairs. They were following a paper-based system, which was inefficient and labor intensive. Each time the track had to undergo maintenance, Track Allocation staff had to complete and submit a detailed paper form, which took more than half an hour to complete and often had transcription errors.
They were able to solve this problem with a Geocortex application called the Track Allocation System (TAS) that leverages Geocortex Workflow and Geocortex Reporting technology. Track Allocation staff can now simply draw a box on the map to select the area and assets where the work needs to occur, and the workflow running in the back-end automatically populates a Track Allocation Request Form.
A process that used to take more than 30 minutes now takes a matter of seconds to complete. The TAS was implemented in March 2016 and already has a user base of more than 160 employees, who have recorded more than 7,000 track allocation requests.