Giving the power of GIS to field technicians
Software Development
The vendor’s product, OUTFIELD.Leak Survey is a Visual Basic shell running on top of a licensed
graphics engine written in C++. In the true spirit of rapid application development (RAD), the vendor had
no definition of a leak survey field system to use as a pattern. It was, therefore, challenging to move from
the utility’s general requirements to concrete specifications. To maintain a flexible development cycle, the
client’s project specifications were loosely defined at the beginning and evolved during numerous
brainstorming sessions.
Programming began in Windows 3.1 l@ with the target being Windows 95@when support for that platform
became available in the core graphics engine. Six weeks prior to the field pilot, the ’95 core was issued.
Again in a RAD environment, the Visual Basic shell was ported to the new platform.
This pioneering effort was successful only because the client and vendor maintained a close partnership
during the development period. The client provided the software developers with feedback and more
specific definitions of functionality as they received input from people experienced in field work.
OUTFIELD responded quickly incorporating the changes as well as solving problems in the software as
they were discovered. Some issues were intentionally left open pending the results of the pilot.
The initial software development tasks included the following:
- Develop a translation of the CAD drawing graphics and attribute data to a format that could be used
by the field GIS. The maps from the CAD system included attribute data such as pipe material, pipe
size, address, and street name.
- Develop tools to navigate around the electronic map, including navigating by address, street name,
street intersection, electronic mapsheet number, and the historical paper map sheet number. The
paper map sheet is needed for transition purposes until all of the applications are developed, if we
are to replace the paper mapbooks kept in the technicians’ trucks.
- Develop a leak sketching tool in the GIS that utilized the Iandbase and facility data. The map area
immediately surrounding the leak would be cut out and integrated with a leak detection report, along
with address, street name, pipe material and size, and the x-y coordinate of the leak. The x-y
coordinate of the leak would eventually be passed back to the mapping system to record the location
of leaks caused by corrosion.
- Develop a client version of the LSLS that would run the leak survey application on the field
computer, including all data valid ity checks that are used in the centralized database.
- Develop a method to transfer the leak sketch and data from the GIS to the leak detection reporting
form in the client version of LSLS.
Unlike most field applications that mostly involve collecting attribute data to fill out a form, the Leak
Survey application involves the integration of GIS data and graphics as part of the final product. This puts
considerable focus on the GIS landbase, addresses, facility locations and attribute data to be accurate in
order to report the leaks that are detected during a leak survey.
Pilot Proiect Plan
The pilot project tasks included:
- Develop a prototype application for leak detection reporting that allows leak sketching and entering
the appropriate leak information.
- Testing of application in office by the System Monitoring staff and the GIS planning analyst.
- Make required software modifications.
- Train field technician in an office setting using sample leak reports on both pen-based and laptop
computers.
- Make additional software modifications.
- Test in field in two separate locations.
“ Recommend additional system modifications.
- Evaluate pilot project.
The leak sketching application was developed by the field GIS software vendor and was reviewed by
System Monitoring management and GIS management. Several changes to the software were
recommended. With the majority of the modifications complete, a decision was made to proceed to the next
step of the project. Although there were still several bugs that needed to be fixed, it was in our estimation a
workable prototype. We were then able to begin training one of the field technicians to test the system for
usability and functionality. At that point, several additional modifications were suggested. Again the
decision was made to complete a reasonable number of the modifications so that the pilot project could
proceed on schedule.
The initial field test was conducted in the same week, in two separate operating areas, by two different
technicians. One technician was vaguely familiar with computers. The other technician had never used a
computer before. One location used primarily a pen-based computer, and the other a laptop with both a
mouse and trac-ball. Initial test results were good, but still several changes were suggested by the field
technicians. Some additional software changes were then made, followed by a second field test in one of the
locations, using primarily a laptop computer. Additional recommendations for software changes were noted,
and discussed with the field GIS software vendor.
Project Findings and Results
GIS Data Accuracy
For the most part, the landbase maps used to create the electronic maps were obtained from the cities served
by LSG. Depending on the accuracy and currentness of their landbases, actual lot locations and boundaries
may not be reflected in the field. In addition, the addressing that is the official record of the town or city
may or may not reflect what is actually used for house numbers or curb address markers. This is especially
true of small towns. LSG serves over 400 towns of 5,000 population or less.
The digitized gas facilities may not be shown on the electronic map in the right location. For example, a
service line may be shown on the left side of the lot on the map, when in the field it is actually on the right
side of the lot. This is a problem when a concerned technician is familiar with sketching a schematic of the
leak that represents the reality of what is in the field versus what the map shows. The technicians’
288.performance is evaluated in part on how accurately they pin-point a leak on a given gas main or service line,
and how well they communicate that information to the repair crews.
The desire to have an accurate picture of what is in the field implies the need to have a redline markup, or
field verification feature to go hand-in-hand with the leak survey application. The millions of dollars spent
on conversion could be seen as ineffective if the technicians feel they are forced to use incorrect map
information.
Map Navigation
Viewing a drawing on the screen does not give the same overall view as that of a paper map. As a result,
when zoomed-in to legibly read the text on the screen, labels for street names may not appear at that scale.
This implies the need to dynamically label the streets when zoomed in on the screen. This could be
accomplished by using intelligent street centerlines. However, a large part of the city landbases do not have
street centerlines, and would have to be added to the maps. The addition of street centerlines would also
help in developing navigation tools.
