Good vs. Bad & Ugly: Comprehensive vs. General Design

The difference between "Comprehensive Software Design" and "General Software Design" and why Comprehensive is the only way. Let's assume a simple categorisation of business into trade and manufacturing. Most of the companies that are active in a category, arrange and manage their processes - despite different fields of business- inspired by a similar and close to optimal pattern. For example all trade companies share the same processes and concepts such as sales region, sales commission, petty cash and etc. The pattern is called best practice . Good Now, imagine that you have designed and implemented information software for 25 trade companies so far; naturally resulting in your extensive knowledge of trade firms' processes and requirements -put simply, best practice. In other words, you do know what the customer wants and needs. What happens if you decide to design a comprehensive information system for trade firms? As you know their requirements...