The World Cup, which reaches a conclusion with the final between champions Australia and Sri Lanka here on Saturday, staged its first competitive match on March 13 when West Indies played Pakistan in Kingston.
But warm-up games were being played as early as March 5.
"We listen to criticism, and there has been a lot of it from people saying it's been too long - so we'll look to make it shorter," Speed told the BBC.
"We'll seek to reduce this 47-day World Cup by seven or 10 days, and hopefully we'll get it down to somewhere between five and six weeks next time."
Speed has also defended ticket prices at the World Cup which, at many venues, were out of reach of the locals.
As a result, the majority of the matches have been played out to stadiums scarred by row after row of empty seats.
Attendance at matches wasn't helped by the shock first round exits of Asian superpowers India and Pakistan, both of whom would have been expected to fill grounds in the latter stages.
"It has cost the tournament in terms of supporters, but it has also shown that cricket does exist outside the top eight sides," said Speed.
"To those people who have said the tournament has been too long, it is worth pointing out that there are three fewer matches this time, compared to four years ago, despite an additional two teams taking part.
"It would have been great if every one of the stadia had been full for every match, but that has not happened."