Future work should attempt to address the above deficiencies, however researchers should not underestimate the difficulties involved in getting access to carry out detailed costing within companies, and should be wary of self reported costs as the basis for such costs may not be easily validated. Future research might also investigate how the total cost of outsourcing varies with:
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different transaction volumes;
experience of adopting outsourcing practices; relationship with the outsourcing vendor; industrial practice; and
different product types.