The document discusses the consequences of spreadsheet errors, including wrong investment decisions, over-promising sales projections, and leading to wrong decisions overall. This can result in long hours of additional work to figure out what went wrong and hurt credibility with bosses and clients. Key causes of errors include failing to carefully design the spreadsheet model in advance, being number-oriented without qualitative interpretation, and carelessness. Different types of errors are discussed such as simple mistakes, mechanical errors, logical errors, and omission errors. The conclusion emphasizes that while people make mistakes, prevention is less painful than fixing errors, and habits of careful design, interpretation, and double-checking should be developed.

1. Spreadsheet ErrorsDFMW 2010 Spring B - Taejoon ParkButterfly Effect: small differences in the initial condition of a dynamical system may produce large variations in the long term behavior of the system

2. Consequence of Spreadsheet ErrorsDFMW 2010 Spring B - Taejoon ParkSpreadsheetErrorsLongHoursof PainfulAdditionalWorkWrong investment decision

3. Over-promising sales projection

4. … etc.Leadingto WrongDecisionNeed to figure out what went wrong

5. Usually very painful process… HurtYourCredibilityfrom your boss