Among the committees are those dedicated to ensuring that foreign assistance programs align with national priorities, that there is a balance between the work done in Washington and in the field, and that the department’s computer system — famously poorly functioning — adopts cutting-edge technology.

Mr. Tillerson has made clear that he believes the State Department is badly mismanaged. In an interview last week, he said he was surprised at how poorly the government’s decision-making process compares with that of Exxon Mobil, where he worked for 41 years, leaving as the chief executive and chairman.

“It’s largely not a highly disciplined organization, decision-making is fragmented and sometimes people don’t want to take decisions; coordination is difficult through the interagency,” he said of the government.

Mr. Tillerson’s only direct experience with government service has been during the Trump administration, which has been slow at filling crucial leadership positions.

Mr. Tillerson has said he expected to come up with a reorganization plan by the end of the year and begin putting it to work next year, an unusually long process for such an effort but one that reflects his commitment to a top-to-bottom review.