Multiple products changes

Your general aim should be to improve product quality, increase productivity, and reduce the cost of development and manufacture. However, productivity is not easy to measure with multiple products on multiple lines, each at a different stage of maturity. This makes comparisons to detect changes in productivity difficult, if not impossible. However there may be factors common to all product lines, such as labor costs. Merely outsourcing manufacture to developing countries may not improve your productivity. The labor costs may reduce but rework and warranty claims increase. Productivity is only improved if product quality has been maintained. Certain processes may also be common to more than one product line and hence improving productivity of common processes can have wide-ranging impact. 

With the involvement of both production and safety/environmental personnel, design intemally-consistent sets of 2-3 alternative overall system changes encompassing multiple component changes related to point 9 above. 

When a reaction involves multiple bonding changes, a question may arise whether the bonding changes occur by a stepwise or concerted pathway. An answer to such a question based on the classical reaction theory is that the reaction proceeds by a concerted pathway, by a stepwise pathway, or by a mixture of the two separate pathways. However, if one takes into account dynamic effects, the answer to the question of concerted versus stepwise may be much more complex. It is interesting to point out here that the case reported by Singleton for the ene reaction affords a case, where stepwise mechanism can dynamically operate on a concerted PES. This contrasts with the reactions described in section Nonstatistical Product Distribution , in which the... 

For single separation duty, Diwekar et al. (1989) considered the multiperiod optimisation problem and for each individual mixture selected the column size (number of plates) and the optimal amounts of each fraction by maximising a profit function, with a predefined conventional reflux policy. For multicomponent mixtures, both single and multiple product options were considered. The authors used a simple model with the assumptions of equimolal overflow, constant relative volatility and negligible column holdup, then applied an extended shortcut method commonly used for continuous distillation and based on the assumption that the batch distillation column can be considered as a continuous column with changing feed (see Type II model in Chapter 4). In other words, the bottom product of one time step forms the feed of the next time step. The pseudo-continuous distillation model thus obtained was then solved using a modified Fenske-Underwood-Gilliland method (see Type II model in Chapter 4) with no plate-to-plate calculations. The... 

Single product vs. multiple product operation—Equipment with more internal parts takes more time to clean when changing from one product to the next. Ease of switching from one product to the next should enter into equipment selection. 

Frequency of product change-out—If multiple product operation is planned, the frequency of changing from one product operation to the next will also dictate the appropriate equipment. Again, cleaning between runs needs to be considered. 

The second approach involves a change of products or their proportionate conversions and may be illustrated by chlorination of benzene. Although monochlorobenzene was the product commercially needed, some o- and p-dichlorobenzene were always formed in the process. These were stored by the wise manufacturer until excellent markets for these products were developed. At present certain manufacturers conduct the chlorination of benzene to make the maximum amount of the dichloro derivatives. Here the unit consumption factor of chlorine, for example, varies with the proportion of the poly-chloro derivatives made. When benzene is chlorinated in this fashion, there will be not one conversion factor but two series, giving for each the conversion factor of benzene or of chlorine to chlorobenzene, p-dichlorobenzene, and o-dichlorobenzene. For this multiple-product manufacture the over-all picture can be obtained only by the summation of the individual product conversion factors. 

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