Over the past decades electric, gas, water, and telecom utilities have poured millions into digitalizing the graphic design/work management and GIS/records management processes. But in spite of this the decades-old as-builting process remains marred by manual paper-based processes that have ramifications for industry and society in general. As-builting is characterized by inefficiency that causes critical processes such as outage restoration to require more time than they should and low data quality which leads to incomplete, out of date and inaccurate underground utility records that are responsible for frequent construction delays, injuries and fatalities for workers and the public, and a drag of billions of dollars on national economies.
Dated, paper-based as-builting workflow
One of the biggest and most persistent problems for almost all utilities is the use of paper in the construction as-builting process. It is a challenging problem that has been with us for decades. The first post of this blog in February, 2006 discussed this problem and in some respects the as-builting workflow has not changed that much since then. Over the past decades utilities have spent millions of dollars digitalizing design (CAD) and records management (GIS), but the gap between them has remained filled with paper. The schematic shows a typical design, construction to GIS workflow that's in place at most utilities today. Design is done using a graphic work design system (CAD) in the office that is integrated with a work management system. A paper job packet is sent to the construction crew in the field who attempt to follow the design drawing. More frequently when contractors take the design drawings out into the field, they often find that obstacles, such as existing utilities or other infrastructure even old tram lines or sewer lines, force them to make changes. After completion of construction paper as-builts are prepared that make their way back to the office to be entered manually into the records system typically a GIS. If the construction crew has had to make some changes, these are supposed to be redlined on the design drawing, but all too frequently the crew simply hit the easy button and check the box that says, "We built it exactly as you designed it." The reality is that 90% of designs change in the field and the changes are rarely recorded. This is a major source of data quality issues and is the chief reason for the general unreliability of utility GIS records. Unreliable underground records lead to construction delays, budget overruns, injuries and even fatalities for workers and the public.
The as-built workflow is also fraught with inefficiencies because many of the processes are manual. The result is massive mapping backlogs. Backlogs of 30, 60, 90 days from construction complete to being entered in the GIS are common. The result is that the utility GIS is always out of date and critical processes such as outage resolution require more time than they should.
If we are to address these issues it is imperative that we improve the way buried assets are designed, constructed, recorded, and managed.
Grid modernization is driving change
As a result of being asked to do many more things than in the past, the grid is being transformed from a centralized to a distributed model. For electric utilities, utility digital transformation is already driven by increased demand for distributed energy resources (DER) such as solar, wind and other renewable technologies. This creates a requirement for an advanced distribution management system (ADMS) which is the intelligence that supports the new distributed smart grid model. These developments are being accelerated due to COVID-19 and the requirement for a more touchless environment for utilities. The bottom line is that for these advanced solutions to provide full value a reliable digital twin of what is out in the field is essential, and right now for most utilities that remains a challenge.
Grid hardening to increase resilience is another major initiative that is contributing to transforming the grid. When a utility experiences a major storm, flood, catastrophic wildfires, or other natural disaster it has to change its infrastructure plans. It may have to move overhead wires underground, move transformers out of flood zones, or ameliorate the risk to substations. The sheer glut of aging infrastructure replacement programs is also increasing pressure on utilities and contributing to a significant increase in construction activity. Grid transformation on this scale with the sheer volume of new construction that it required is forcing utilities to find ways improve productivity by managing construction data from source to consumer digitally.
As-builting remains a persistent problem
However, a major source of construction inefficiency remains. Why, after decades of growing awareness of the inefficiency and data quality issues associated with the traditional as-builting workflow, are construction as-builts still recorded on paper ? First of all, there's resistance to change. Utility construction is managed using a variety of manual, paper-based processes that have been in place for decades. Secondly, there's the aging construction workforce that has always relied on legacy processes and has not seen reason to change. Another problem is that well-established enterprise systems such as asset management and GIS don't provide the comprehensive solution that construction crews need to digitalize the full process. Those systems are designed to support long cycle construction projects which typically require a month of planning and may not be completed for six, nine, or twelve months.
An important factor that makes this problem so persistent and difficult to resolve is the many personas involved. The as-builting workflow is tasked with taking highly technical engineering output from the designers, translating it into instructions that a construction crew can use to safely build the job to code and to standard, then asking a field engineer to draw up the as-builts, and converting those paper drawings into geospatial data that a GIS technician can use to update the utility GIS. Technically this is a complex process that involves distinctly different personas that work in different teams with different technical vocabularies, different training, different software systems, and who are measured by different goals and performance indicators. It is further exacerbated by a lack of clarity as to who owns the as-builting process, engineering, construction, or records/GIS. The designer may point to the contractor as the owner. The contractor might think the GIS technical team is responsible and records/GIS group may think that the designer owns it. Often the real answer is that no one owns as-builting and that is the operative reason the problem has been so persistent for decades.
Digitalizing the as-builting workflow
To improve the efficiency and data quality of the as-builting process digital tools are required to help utilities bridge the gap between the design and the system of record. The key technologies making this possible are mobile applications and mobile devices, cloud technology, and the availability of economical high accuracy GPS. To be successful the tools need to be adapted to the different personas. For the construction crew end user persona a mobile first philosophy is essential to enable real-time data capture in the field. This requires easy to use mobile apps supplemented by high accuracy GNSS and devices such as bar code scanners. Together these make possible the efficient capture of survey grade data and associated metadata greatly enhancing the speed, accuracy and fidelity of the data feeding the utility systems. In addition a digital data stream makes it possible to update the system of record more rapidly. This result is the records/GIS to become more effective in producing reliable as-built records that locate and construction crews can rely on. For utilities that have adopted this approach, enabling field crews to digitally capture construction data is now a best practice.
Example: Digitalizing the mapping of underground duct banks
As a real world example a contractor serving some of the largest utilities in the West Coast of the U.S. was faced with new requirements for the construction project they were working on for a utility customer. They were now required to capture GPS locations real-time during construction. Precision was required to be two-tenths of a foot (2.4 inches) or better and location data points were to be collected every 25 feet for linear assets. The contractor had not had to meet requirements like this before on a major project. The scale of this project made the new requirements even more challenging; 35 sites throughout the Central Valley of California, 35,000 feet of trenching, auger bores under highways and railroads, and many primary enclosures.
Fortunately the contractor had had experience with digital construction processes on smaller projects. Based on their previous experience, they were convinced that a member of their own construction crew already on site could capture the location data with the required precision. Having in-house capability for capturing survey grade construction data would allow them to deliver the data without having to have a survey crew on-site or managing outside survey crews. The benefits they hoped to realize were cost savings associated with not having to hire an outside survey crew and related intangibles such as not having to coordinate schedules for survey crews and holding up construction while waiting for survey crews to arrive. However, they were concerned that the the additional training and work load required to capture location data could potentially disrupt their construction crews' schedules.
Key project achievements of digital construction workflow
The implementation of the digital workflow by construction crews actually proceeded rapidly. Crews were capturing survey grade GPS data within days. Over a period of six months using the solution at 23 active construction sites, over 16,000 feet of buried linear assets, including duct banks and tracer wires, were mapped and some 5,000 supporting photos along the way were captured. The median GPS accuracy of the data captured by their construction crews was 0.14 feet, a remarkable achievement that exceeded the project precision requirement. Their customer even requested them to go back to pothole and capture accurate locations for trenches that had already been covered over before they began using the new digital process. The many photos that were collected along the way and geotagged to specific locations provided a valuable record of everything that was done in the field for future reference.
Benefits of digital construction workflow
One of the important results of the project was that their initial concern that digital capture in the field by construction crews might disrupt the crews' daily routines never became a problem. Construction crews were able to collect as-built data from open trenches using mobile devices with high accuracy GPS without disrupting their normal processes or impacting their schedules. An important cost benefit was that they didn't have to employ and coordinate survey crews. Instead of calling in a survey crew they were able to employ one of their own crew members who was already on site to capture survey grade location data. This resulted in an estimated project time savings of around 20%.
An important advantage of the the digital construction process they used enabled them to spot when crew members' shots did not achieve the required project precision. The ability to identify and flag data that exceeded the 0.2 foot accuracy requirement and needed to be repeated was an important factor in achieving the overall project precision goal. Flagging low precision data also avoided the costly process of having to send a vac truck out after the trench was filled to do potholing and retaking shots. Another benefit was automated close out enabling them to receive automated data exports without having to do any paperwork.
The major achievements of digitialization were that survey grade as-builts could be captured in near real time with no disruption to construction crews' schedules, the utility GIS rapidly updated and able to provide up to date, high accuracy underground utility records and all of this at lower cost. Overall the project realized an estimated cost savings of around 50% mainly because fewer man hours were required.
This post is based on Danny Petrecca's talk at the Canadian Underground Forum (CUF). You can listen to all the talks at CUF on the GeoIgnite CUF Youtube channel.
Subscribe
Comments