In terms of similarities, Both EFQM and Six sigma serve as tools for continuous improvement . EFQm is continuously updated with tested best practices for various organisations, while companies try to achieve the six sigma level of 3.4 defects per million, even though many companies haven't achieved it, they continously improve the get to the six sigma level.
Both EFQM and Six Sigma require top management for the successful implementation of both tools because if senior or top management doesn't see the importance of either tool, the implementation would not be successful and money spent on training would be wasted. An Example of this is when motorola first decided to implement quality training and six sigma in their organisation, but they made the mistake of using the bottom up approach by training the workers first before training the managers, their first attempt was unsuccessful because when employees went to ask their bosses questions relating to improvement of quality in the organisation which the bosses could not answer because they had not been trained.
Implementation requires a lot of time and training for both six sigma and EFQM and a result implemetation is quite expensive because of the money that will be spent on training and the long pay back period before the results are seen.
In Terms of differences between six Sigma and EFQM, Six Sigma seeks to reduce the variations in processes by finding out the cause and eliminating it, while EFQM tries to achieve sustainable excellence.
Six Sigma looks at Individual projects in an organisation while EFQm takes a more holistic approach by looking at the entire organisation.
Six sigma tries to reduce scrap and rework and involves fluctuation performance measures for managers, while EFQm tries to improve the overall quality of the management system.
I believe, that EFQM and Six Sigma are very good tools for Quality management and EFQM can best be used in the entire organisation with Six sigma used for the different projects that the organisation to improve the overall quality of the Organisation.