While the MBTA struggles to improve it's performance, managers at the T are also trying to figure out exactly what performance means.

The MBTA Fiscal and Management Control Board here a briefing Monday on a plan to revamp the agency's metric for service delivery to bring it up to date and make it a useful tool for long-term planning.

Basically, the T wants to set up a new system to gauge rider satisfaction in a quantifiable way so they can better plan how to manage the system.

One big change is that the T wants to shift away from counting just train performance and factor in riders more. For instance, more crowded trains will mean more than empty ones.

"So instead of measuring, is the train on time, we're measuring were the passengers on time so that it kind of gets at what the passenger experience is," said Laurel Paget-Seekins, the MBTA's Director of Strategic Initiatives.

The old system, the T reports, is based around operator experience - equipment stability, on-time performance and the like - and not the passenger experience.

The MBTA wants to measure the availability of service in all its areas, the reliability of that service, the comfort of the ride and its accessibility to the disabled. Another factor is how cost-effective all these positive elements are. Newly added to the list of objectives for the first time will be  communication, how well riders feel they're getting updates on service.

In the end, the MBTA hopes to create a new "performance dashboard" riders can monitor to see how well the service is doing.

It would be the first major revision to the T's Service Delivery Policy since 1996 and only the second since 1977. A lot has changed since the mid-90s, now that riders movements and payments can be tracked much more accurately. Data collection has given the MBTA a wealth of information on ride-times, capacity and on-time performance that the agency is now looking to utilize to get a better sense of how it performs.

The MBTA surveyed about 6,000 riders through online questionnaires about rider preferences and priorities. One question asked riders if they would board a train under various situations ranging from a nearly empty train to one packed beyond capacity (Think game day on the Green Line.) The survey found that just over 60 percent of riders would not get on a train that has 4.36 passengers per square meter of space. That number jumps to almost 90 percent at 6.29 passengers per square meter.

Twenty percent of respondents said they would get on a train no matter how full it is, no matter what. You know those people. We all know those people.

MBTA Potpourri

- There's good news for the machinists that work on the T. After being reported as the only area of the T where absenteeism went up after the adoption of new leave management policies, it turns out that wasn't the case. A management glitch incorrectly counted a certain category of leave as unexcused when in fact is should have been excused. With the correction in place, MBTA chief operator Brian Shortsleeve reported at Monday's board meeting that machinist absenteeism was actually down ten percent.

- The T hosted the fifth in a series of public meetings on potential increases to fares Monday morning at their headquarters in Boston. There's another meeting Monday evening in Worcester and another Boston meeting at 5 p.m. Tuesday and one in Newton on Thursday.