User talk:Brindis

Dear Brindis

Thank you for your countribution in article of process industries .I have read your commentary but unfortunately I have to chaneg some of it.First of all you can find classic definition of process indiustries in http://www.iienet2.org/Landing.aspx?id=887 as a below:

What are the Process Industries? The process industries are those industries where the primary production processes are either continuous, or occur on a batch of materials that is indistinguishable. For example, a food processing company making sauce may make the sauce in a continuous, uninterrupted flow from receipt of ingredients through packaging. Or, batches may be produced depending on the cook kettle sizes but immediately combined and re-routed. In either case, there is no concept of a unit of sauce while it is being processed. Examples of the process industries include food, beverages, chemicals, pharmaceuticals, petroleum, ceramics, base metals, coal, plastics, rubber, textiles, tobacco, wood and wood products, paper and paper products, etc.

Based upon mentioned definition, I couldnt believe the discrete manufacturing systems such as Auto parts production lines can be categorized in process industries. I will be happy to hear from you in( rz.hosseini@gmail.com) or in this web site enthusiastically.

with best regards

Reza Hosseini

Yes, some people prefers to separate discrete processes from continuous/batch processes. Some other prefer to keep them together. In fact, is many cases there are a "mix" (think for example a liquid detergente or automobile oil manufacturing process: the detergent/oil manufacturing is continuous or bacth, while the bottling is discrete). Some cases are difficult to classify... I prefer to put all of them together. The definition you give is not quite good anyway. E.g. there *is* a "unit of product" in a batch process, though the unit is not a bottle. And the example is bad: the contents of the kettle may or *may not* be combined and re-routed. The most easy way to differentiate continuous from batch is: - in continuous process, the process is most of the time in steady state (e.g. start/stop time is very short compared to production time) - in batch, the time the process is in steady state is comparable with the time it is changing There are 2 kind of batch processes: - in some, production is steady but production time is comparable with start/stop time - in others, production is almost never steady There is another way to caracterize batch processes but it is not always true: when lots of products are made of lots of raw materials, i.e., if you take an amount of product you can relate it to the raw materials used. But in some cases (e.g. ice cream processing) part of the product is reprocessed, so different lots of raw materials *and* products are mixed together. (for tracking purposes, anyway, after a number of reprocesses it is said that the oldest raw materials are not present any more)

Ok, that all but anyway I see that the original article changed a lot :-)

Jorge