Our clients from information industry often need "something" that helps solving problems in complex project management and information security. Project take more time, the output is not error-free and overall costs are usually higher than expected. Necessity to choose between two unbearable options - expenses and security is necessary in any information technology project. Creation, implementation and maintenance of security requires complex thought and widely used spreadsheets disservice in complex environment, but the mistake is discovered when it is too late.
We are building decision support simulators for our clients who solve problems more complicated than spreadsheet can successfully sustain. Spreadsheet is a fine tool when the problem at hand is simple and static. That means - it does not change over time. Spreadsheet is also sufficient when relationship between variables (cells) is liner. Spreadsheet is unable to cope with delays. When there is no delay in what you're solving (like reaction to your policy) you are still fine with the tool. Another thing you have to omit in your spreadsheet calculation is a feedback. All of the questions above form a feedback structure but you won't see it in you table. Any attempt to create circular structure will end up in error message in spreadsheet. Simply stated, you need a better tool to answer questions asked above or any other you may have.