I would suggest taking a look at the work of Nonaka (1991, HBR; 1994, Org Science) and Ambrosini and Bowman (2001, JMS).  You may also want to look into research on expertise and expert performance; particularly the work on the elicitation and representation of expert knowledge (see Hoffman & Lintern's 2006 chapter in Cambridge handbook on experts).  Keep in mind, however, that the topic of tacit to explicit knowledge conversion has certainly involved debate and differing of opinions in respect to whether such conversion is possible (e.g., see Tsoukas' 2003 chapter in Blackwell handbook on org learning and Nonaka & von Krogh's 2009 Org Science article).  For more general background on knowledge retention mechanisms, I would suggest taking a look at the work of Walsh and Ungson (1991, AMR) and Youndt et al. (2004, JMS). 

Thanks Rory, you have provided me with great insight.

You could send in some anthropologists who apply ethnographic methodology within the organizattion. The Researchers would listen to the stories that employees tell about their routine work. Often organizational (tacit) knowledge can be collected in this way. E.g. Paddy O'Toole 2011 "How organizations remember". A more formalised method for doing this is "Story telling", see Thier/Erlach 2005: The Transfer of Tacit knowledge with the Method „Story Telling“, in: Knowledge management and narratives : organizational effectiveness through storytelling / ed. by Georg Schreyögg pp. 123-144. 

Thanks a lot Svenson, your response will be of immense use to me

Justin, the issue of individual knowledge and the creation of organisational memory that this may lead to and enhance, has been a long standing issue of debate and discussion. Some of the ways that have been advanced in order to enhance such mutuality include, but are not restricted to the following methods such as identifying which staff have what types of knowledge, skills and competencies in order to collate a knowledge and competencies bank, identifying retrieval and storage mechanisms within departments, encouraging a range of cross competency role working with the aim of mentoring those who are less competent, shadowing those who are skilled, documenting and using the sum total of knowledge over time. Interesting.