VOFM is a tool that was developed in R/3 to faciliate the definition of both SAP delivered as well as customer defined routines/rules used in the system during various business processes. VOFM routines are ABAP code written in Forms. VOFM provides the user with the benefit of choosing from one on the standard deliveried R/3 routines or writting their won. OVFM is inteneded for the implementation team when configuring the system. It is not intended for the end user.

Scale Condition: 就是根据客户购买某个物料的数量来计算不同的价格。例如，买白菜10斤以下1元/斤，10斤以上，0.8元/斤。Scale formula可以被用来指定特殊的价格。

Group Condition：类似于scale condition,但是这里考虑的不仅仅是某个物料的数量，而是整个订单的数量。Grpcond. routine 也可以指定不同的计算逻辑，例如，整个订单数量，所有的条件类型的总和。

找到上述文件的官方地址了

http://www.saptechsolutions.com/solutionsguide.htm

价格差不多了，因为环境上边都没有开发权限，没有办法亲自试验。有机会的话，还是要自己做做form看，肯能还会有些问题。