Haas scored all but one of its 12 points in the first five races of the year, with a best of seventh place earned by Hulkenberg in the high-attrition Australian GP.
The German said that once rivals began to develop their cars Haas slipped back and its issues – notably with overheating tyres in races – became more obvious.
"Obviously, it was a process, and signs were there early in the season," said Hulkenberg when asked by Autosport about the team’s frustrating year.
"But we got away with it early in the season because other people also were struggling more.
"And then once they cleaned up and then brought some real developments, that's when we really started to pay the penalty.
"The last or the second half of the season has been really tough. I think there was only an opportunity to score a point or two for me in Singapore, which we missed by the wrong strategy call.
"Apart from that we just never had the pace to do it. Even when there were a lot of cars dropping out, we were just too far away from it.
"So of course that's not great. That's why we need to do better."
Hulkenberg admitted that splitting the car specs in Las Vegas and Abu Dhabi, with him in the older car and the Kevin Magnussen the new version, highlighted the lack of successful development.
"I don't think there's a huge difference between them," he said. "Minor differences. Last weekend [in Las Vegas], I felt actually the new package had an edge over the old package on a low downforce configuration.
"This weekend, obviously I didn't do the Friday, but from Saturday, I felt quite okay. Kevin didn't feel so happy. I mean, both are similar.
"But that's in itself obviously is not good enough. An update is supposed to be better, and fix some of your issues, and unfortunately that didn't happen. So, we need to try and do better there next year."
He added: "We just need to pick up our feet, and do a better job, we need to work hard, because we want to do better.
"I want us to do better ultimately, and I think everyone in the team wants to do better. So we just have to try and come up with better solutions."
