The manufacturer jumped two places since last year to claim the title, toppling British American Tobacco, which slipped to 19.
Insurers Aviva jumped from 16 to second place, displacing Unilever, which slipped to 15, while engineering group GKN took third place, moving up 43 places to replace Diageo.
Dr Roger Barker, director of corporate governance and professional standards at the IoD said the sector breakdown was instructive.
“Energy companies tended to do quite well, with scores above average, whereas the sector that did less well was the technology sector,” he continued.
“This is consistent with what we’re seeing in the US, with a lot of big tech companies having governance issues of late.
”That gives rise to the question, is governance an issue in that sector? Because these companies are growing rapidly and are still growing often with their founders at the helm, perhaps their weaker governance score reflects these growing pains,” Barker added.
The top 10 are:
- Smiths Group
- RSA Insurance
- International Consolidated Airlines
- Intercontinental Hotels
GlaxoSmithKline was the last name on the list, dropping 64 places since last year’s line-up.
The final 10 are:
94. Rolls-Royce Holdings
96. Burberry Group
97. BAE systems
98. Standard Chartered
100. Anglo American
The third annual report was compiled using research and surveys of stakeholder perceptions of corporate governance.
Factors assessed included how a company was run, board diversity, director’s pay, the length of time the company had been without auditors and whistleblowing policy.
However, Barker noted a caveat to this year’s research, as the IoD has expanded its number of measurement indicators from 34 to 47.
“In a way companies are being measured on a slightly different basis. Hopefully in the future we’re going to reach a stage where we have more maturity.
“Having said that, a lot of the companies that finished near the top in previous years have also finished near the top again. There is a reasonably fair degree of stability,” he added.
At the end of August, prime minister Theresa May faced criticism after the government launched what some claimed was a diluted version of corporate governance reforms.