Ivory tower gets wheels
Case Study – Public Service Company of New Mexico (PNM)
Before describing the use of mobile computing at PNM, we should provide some context.
Public Service Company of New Mexico is based in Albuquerque, New Mexico, with
approximately 360,000 electric customers and 400,000 gas customers in a service
territory of about 70 square miles along the Rio Grande Corridor meandering about the
Rio Grande River. There are 5300 miles of gas main footage in PNM’s model, 7440
miles of primary wire, along with 76,441 transformers, and 315,000 addresses. PNM
captures both gas and electric distribution facilities in their viewing environment; and is
used by approximately 200 employees, both in the field and on the desktops.
PNM had three primary goals for mobile computing:
- Decrease the time it takes a crew to find a service location.
- Make the most accurate data available to crews.
- Provide a means to capture more intelligent maintenance data that might in turn
help target inspection dollars in the right direction.
In the process of achieving the primary goals, PNM gained a number of benefits that had
not been anticipated:
- Decrease dependency on a paper ‘trouble book’, an unwieldy book that requires a
flashlight if used in the dead of night and is difficult to navigate when a feeder
outage spans several pages. The trouble book updates are not as current as the
data on the mobile viewer, and current data is an important requirement. Finally,
it is very expensive to print; it accounts for approximately $50,000 per year in
printing costs for 5 divisional books totaling 1300 pages. Though the books will
remain as backups in emergency crew trucks, they are less necessary for the folks
that have the same viewing environment on their desktops.
- Reduce downtime caused by address resolution. Trouble crews, line spotters and
some meter readers no longer need to pull paper maps for service addresses or gas
routing information, nor do they need to call mapping and dispatch personnel
during their shift for this data.
- Continually purify the data. Field crews provide corrections to the data at the
time of inspection, a crucial task that would be expensive to do after the fact.
Users of mobile products at PNM include 25 emergency or maintenance line crews, 12
electric and gas line spotters and 8 electric and gas designer/service managers. The
emergency line crews are expected to respond to outages around the clock, so having
facility information immediately accessible means shortened customer outage minutes.
These crews also need to measure fault distances, and can do this readily with a
‘measure’ command in the viewer environment. To measure these fault distances from
the paper trouble book, that may span several pages, would be difficult, would take
longer, and would be prone to error. So the viewing tool saves time in restoring service,
and just as importantly, provides accurate outage information to take back to the office
and use in reporting. Maintenance line crews provide scheduled maintenance on electric
and gas facilities, and for the same reasons as the trouble crews can complete a job faster
and with more accurate information now that they have mapping data at their fingertips.
The earliest mobile viewing users were the electric and gas line spotters, who began
marking cable locations for construction crews in 1996 and continue today. The last
large field group to make use of the facility data are the crew foreman and designers.
Formerly, the designer would often have to make multiple trips out into the field,
reconciling the design on paper with what was shown in the field. Now they have the mapping data with them for the initial site visit, and a tool that allows them to take field
notes, letting them finish the design completely in the office without a second trip to the
field.
Two applications have been especially effective at PNM and a third is planned:
- GPS Truck Locator – This application is written in VB Script and blends
programming expertise with some GPS know-how. For those laptops without an
internal GPS unit, we affix an external unit that sits on the dashboard of the truck
and power it off the battery charger. The application is launched from inside the
viewer software. The software would normally require an input of an address or
intersection to find a service location, but the GPS function lets the user select an
icon on the toolbar and the application locates the truck position without any
additional input. One button click locates the crew’s position! To enable such
ease of locating, the lat-long coordinates are continually being received from the
GPS unit and captured in a text file at regular three-second intervals. When the
Truck Locator icon is selected, the last coordinate is converted to an X,Y
coordinate, the format used by the mobile viewer, and then passed to a function to
‘view center’, which centers the position of the truck on the screen at a prescribed
zoom level, accurate within a few feet, which is enough to locate the truck’s
position relative to the correct pole. It is much faster than querying for an
address, and many minutes faster than relying on their geographic knowledge of
the service territory when there is no address in the model. Drivers would have to
find the appropriate section map, find the interstate, spot a drainage ditch, and
navigate to the location. For crews that are in rural areas where correct
addressing is less than perfect, this becomes a critical function. In addition, pole
numbers in our model are generated internally from the software, assigning vastly
different numbers to poles than the legacy system used in the field for so many
years. This makes the poles un-navigable by a standard pole number query and
makes this GPS application a critical time-saver.
- Automated Line Patrol System – We are required to capture maintenance data on
all distribution poles in our service area. The mobile viewing environment is used
as the front-end to the maintenance application, just to provide the pole number as
input to the pole maintenance database. The GPS application described above is
used in tandem with this application. The crewperson locates his or her position
in the view screen using the locator icon, then selects the pole on which inventory
will be taken. This number is validated against the same occurrence of the pole
number in the database. The application then launches a series of maintenance
screens, and the role of the map viewer ends; but the requirement for the crews to
initially validate their position and pole location was provided with the map
viewing application. Some of the maintenance data will be uploaded back into
the source AM/FM data, but the main objective for the inspection application was
to provide an effective mechanism for tracking pole data that would allow
analysis based on feeder circuits, rather than geographic areas or boundaries that
had no relation to feeders or any intelligent grouping of facilities.
- Future Application – An interface is planned to a ‘Gas Statistics’ application that
will replace all gas main and service cards with on-line data capture of all gas
facility data (leak survey, cathodic protection, mains and services, etc.).
Associated field notes will be drawn on the map and archived as an image file.
The hardware and software to support mobile computing can make the difference
between acceptance and failure. At PNM, field workers use laptops with rugged hard
disks, hi-brightness screens for optimal outdoor viewing, and touch sensitive screen
displays. They have different mounting bracket configurations based on the hardware
platform. Some have brackets with all the cable mounts in place so that the crew just
slips the unit into the cradle, while others have more primitive mounting brackets.
Figure 1 – Laptop mounted in vehicle
Becoming Mobile / Acceptance at PNM
Acceptance from all of the users has been phenomenal – in most cases, folks were
unhappy to have to wait for their hardware. The line spotters were ready to buy in with
barely a glance at the product, and formal training couldn’t be provided fast enough to
make it worthwhile. After some quick demonstrations of the queries, and some training amongst themselves, they were using most of the tools it provided. A year later they
were asking how to submit field notes of data corrections within the mobile viewing
environment to hand off to mapping personnel, a task that few field crews had been
willing to do because it delayed the completion of their own work. The care of the
hardware was the most prominent issue. The earliest laptops were partially ruggedized
but had no mounting brackets, so they were prone to damage. Plus the screens did not
hold up to the rugged field environment. At the threat of not having any spare hardware
when one unit was off to the vendor for repair, the field personnel quickly learned to
assume ownership for the units and take better care of them. The data updates were
initially handled by IS support, with the intention of easing users into the role of setting
off their own data update routines at their own convenience. In fact the line spotters were
eager to run the update scripts more often than IS could easily support them, and they
took the task on themselves.
For the trouble and field crews the acceptance was just as remarkable, usually due to the
testimonials of other users. Formal training was offered, and foremen had their crews
master the viewing environment on desktop PC’s before tackling the nuances of laptops,
not only with a GPS attachment, but also with a much smaller keyboard, or none at all. A
three-hour formal class at the desktop, followed by an hour of GPS and mobile unit
training seemed the right combination of training.
Lastly, choices in hardware helped acceptance by being both reliable and easy to use.
Most units had touch screens that made the dainty fingering of a keyboard totally
unnecessary for the large hands of most crewmen. We matched the ruggedness of the
hardware to the jostling the units would get in the different field applications. These
hardware and software choices have been hugely successful in gaining the acceptance
and the continued favor of the tools by field crews, who are not necessarily technophiles
but are primarily interested in how useful these tools are toward improving the
effectiveness of their work.
