We mentioned previously that Rabbenu the Ari z"l was very particular to always have a Hazarah (repetition) after the silent 'Amidah (Lahash) of Minha. see:
http://www.atorahminute.com/2009-11-09
He writes that one must never do away with the Hazarah during any of the three prayers which have a repetition, Shahrith, Musaf and Minha. He revealed that that the Hazarah was at a higher level than the silent 'Amidah itself and that both the silent 'Amidah and the repetition were an obligation. Therefore, when the Hazzan was reciting the repetition, the Ari z"l would close his eyes and listen intently to the words of the Hazan during the Hazarah.
It says, therefore, in Ben Ish Hai, that one must never omit the Hazarah when praying, except in a case where one has no choice, such as where there is no time left.
Note: A Hazarah, obviously, can only be done in the presence of a Minyan.
(See Ben Ish Hai, Parashath Terumah, Yr 1, Oth 2. Kaf Hahayim, 124, Oth 2)
