The interim chief executive of the Scottish Qualifications Authority has unveiled a catalogue of internal problems ranging from rivalry and concerns about bullying to inadequate planning and software testing.
Bill Morton this week made a public apology for this year's fiasco, which left thousands of candidates with inaccurate, incomplete or missing examination results.
Giving evidence to the Scottish Parliament's education committee, he said 16,700 candidates and almost 3 per cent of the results had been affected, rather than the SQA's initial estimate of 1,400.
Leading figures in the SQA have already professed themselves baffled by what went wrong, but in a written submission to the committee, Mr Morton said that while poor data or information management lay at the heart of the problems, there were other contributory factors.
Mr Morton's internal review has found that in the absence of proper planning and preparation for the new Higher Still examinations system, "largely ad hoc solutions were attempted as successive problems appeared".