Thesis dilemma

I wrote the following in the introduction section of my thesis:  At first glance, it might seem that ERP Enhancement Management (EEM) is merely a special case of Engineering Change Management (ECM); whilst there are similarities, there are also significant differences which are discussed in the literature review and synthesis chapters. The most significant difference is that ECM is concerned with product management, whereas EEM is concerned at root with people management. This statement implies that the topics of change management and user resistance are relevant to EEM: even the most successful enhancement on paper will fail if no user is prepared to use it. Furthermore, in the researcher's opinion, ECM is concerned with developing physical products which are used by people outside of the developing organisation, whereas EEM is concerned with software and business processes, both non-physical entities, which are used inside the developing organisation.

My supervisor wrote as a comment: Might be worthwhile looking up the definition of a product and a service and using this to support your view concerning the difference between an ECM and EEM.

I looked for a definition of a product and found this: A product is the item offered for sale. A product can be a service or an item. It can be physical or in virtual or cyber form. Every product is made at a cost and each is sold at a price.

According to this definition, an enhancement is a product as it is a service in virtual form; it is made at a cost (employee's time) and is sold at a price. Whilst in-company enhancements are not offered by for sale and are not sold at a price, an enhancement which I might develop for an external client certainly is sold at a price. I can't use this quote to 'support my view concerning the difference' because it seems that there is no difference! Even my emphasis about 'outside' and 'inside' does not cause a difference when one considers (again) the case of a consultant. One can't say that a product is mass produced and than an enhancement is bespoke - my automatic reaction to the word 'bespoke' is tailoring a suit (or a dress) specifically for a client.

Yet I am convinced that there is a difference. I think that I will have to pass this topic on to my right hemisphere in the hope that it will provide a solution to my dilemma.