Dr Poutasi made her comments after appearing before a parliamentary select committee to answer questions about NCEA assessment.
National MP Paul Foster-Bell queried why his niece could this year complete two paper-based exams on the same day. Dr Poutasi said the progress being made meant that was unlikely to be the case for long.
"There is an attractiveness for schools in an ability to get away from that big end-of-year [assessment]. As long as the disciplines and robustness can be assured. And that's our job."
NCEA internal assessment was already carried out close to the time of learning, rather than waiting for an end-of-year assessment, she later told the New Zealand Herald.
"Teachers find that really helpful ... and can see what the benefit would be of being able to have external exams in a similar format. We are quite a wee while away from that.
"Progressively you might be able to move into that environment [any time, online]. The first steps you would make is you would do it twice a year, and then move from there.
"The big ambition is assessment as learning -- so it is so integrated with learning, that you are completing it as you go."
NCEA achievement levels have been increasing. Since 2009, there has been a 9.6 percentage point increase with respect to those who attain at least NCEA Level 2 or equivalent, with 77.1 per cent in 2014 compared to 67.5 per cent in 2009.
Dr Poutasi told the committee that the increase in achievement reflected a number of factors, such as students and teachers becoming more used to the NCEA system, but the overall system was sound.
That was because of a rigorous monitoring and moderation of grades given, both at the school level and by NZQA.
The Auditor-General had expressed confidence in NCEA, Dr Poutasi said, and a school could even have its ability to assess removed in the most serious cases.
"[That happens] very rarely. I can think of once, relatively recently. We don't go there lightly because of the inconvenience for students."
Last year a Herald analysis of NCEA entries showed how much better students can do when they are internally assessed than when they are put under the pressure of an exam.
The difference in achievement rates between the two types of assessment can be nearly 50 per cent, although the gap differs according to subject, level and school decile.
Internal assessments are set and marked by teachers, with grades checked by other teachers and samples in turn checked by NZQA. They can often be re-sat by students, unlike exams.
Dr Poutasi said NZQA was "absolutely happy" with the current situation.
"There will always be a gap ... in your normal daily work, very rarely do you have a sit down, do these things in this timeframe, don't have access to anything. Internal is far more sensible.
"[External exams] will continue to be there in the foreseeable future. The trick for us is to say, 'Well, how does that become more realistic' -- and not just digitising a current paper."
