They should represent different company sizes. Four companies, two small, one medium sized
and one large company were found. They should furthermore be willing to participate in
the study.Oftenmore than one respondent per casewere needed to get information both on
supply chain PM issues and ERP system implementation. Such an approach, to use
multiple sources of evidence, strengthens the construct validity of the study (Yin, 2003).
Personal interviews, conducted by both researchers, were conducted during 2009
(Table III). Case companies A-C have implemented ERP systems with fewcustomizations
for supply chain PM, while case Company D has implemented an in-house developed
best-of-breed solution for supply chain PM.