Positioning by product process can be explained by a simple question. Do you know at what price does human made paintings sell? Its sells at a premium value depending on the artist. The same paintings can be reproduced through machines, photoshop and a normal printer. The value however goes to the the creativity and the way the paintings have been done.
This was a simple example of positioning by the way products are being made. The way you make a product is also important for its pricing. A hand made designer dress will always be costlier as compared to a machine made dress. On the other hand, hair dressers and spas can charge more depending on the process they undertake, the hair cuts they can give and whether or not they use special equipment to service the customer. Thus positioning by product process is getting more importance nowadays.
One of the markets where product process matters the most is the alcohol market. Take a look at the wine market. The age of the wine as well as the make and the ingredients effect the pricing along with consumption.
Engineering products are also known to differentiate themselves through product qualities and manufacturing capacity. Thus positioning can be done by the way a product is produced. Globally we can see that China is known as the king of mass productions. This is because China has positioned itself by as a low price manufacturer because of its product process.