National Grid is head of schedule in its effort to restore power following widespread outages following Hurricane Sandy, according to company President Marcy Reed.

Reed, speaking to reporters in a conference call from a Chelmsford parking lot on Wednesday afternoon, said the company’s estimated restoration times were based on having three-quarters of its customers restored by Thursday night.

“We are already there,” she said. “We are progressing ahead of schedule.”

As of 2 p.m. on Wednesday, 78 percent of the 237,000 National Grid customers that were without power statewide had been restored.

In Andover, as of 3 p.m., 8 percent of the town – or 1,127 customers - remained without power.

The estimated restoration times, released late Tuesday night be National Grid, are for the last customer in each community to get their power restored. In both Andover, that is 11:59 p.m. on Friday.

“We are pressing ahead as we always have been,” she said, adding she expects that a majority of the customers still without power will have it back by Thursday evening statewide.

Crews continue to work 16-hour shift with eight hours off, she said.

By the end of Tuesday, half of the customers had power restored in the first full day after the storm pulled out of Massachusetts. During Hurricane Irene and the “Snowtober” snowstorm just before Halloween last year, that mark was not reached until at least day 2 or day 3 in most communities.

“We were quicker out of the box” in Hurricane Sandy, Reed said.

The creation of the “community liaison” position, which puts a National Grid employee in the emergency operations center of each community, is one of the big changes that have been made since National Grid’s response to the two storms last year came under sharp criticism.

While the company has heard “very good feedback” on that position, Reed acknowledged that there is still work to do to make the position more effective.

“In some towns we still have some bugs to work out” with the way to community liaisons positions operates, she said.

Reed said she would continue to visit towns hard hit by outages and listen to local leaders feedback about the company’s response.