For manufacturers of customized software and their clients it is recommended to expressively lay down in writing for what period the technical support has to be ensured. The entrepreneur should not blindly accept any support agreement which does not contain any clause on a minimum agreement term. This minimum term usually corresponds to the depreciation period (three to five years) or to how long it takes for the software to amortize itself, says lawyer Dr. Gero Himmelsbach in the October 2005 edition of the VNU magazine Computer im Mittelstand. Only then costly complications as occurred in the Fischer case can be avoided. 