Simon is designed to be easy to use. To maintain its simplicity, its designers have limited Simon’s current capabilities. Mathematically, Simon uses a weighted sum to reach an overall recommendation from the results of its separate tools. At this time, Simon automatically determines the weight for each tool’s recommendation as it computes an overall recommended course of action. In a future release, Simon may allow you to manipulate the weights given to each tool’s result to yield an overall recommendation.
Simon does not at this time take into account the uncertainty and/or preference trade-offs that are part of every important decision. Its recommendations are not optimal in any strict sense of the term, and they do not meet the criterion of admissibility. Over time, as Simon’s capabilities are further enhanced, it may increasingly address uncertainty, preference trade-offs, and, eventually, optimality.

As you can see in the "Decision Summary" at the end of the decision process, the result of each tool does not come from a simple, straightforward addition of scores.

In order for Simon to calculate the best option for each tool, he takes into account all of your inputs while using his decision tools and how you rank and score each of these against each of your alternatives. Simon’s algorithm combines qualitative information with a mathematical process and assigns individual values to each input, the sum of these values times it score will give the best option for a decision.

Sometimes the results between alternatives are very close or there is a tie. Although Simon’s algorithm is designed in a way to avoid ties between alternatives, mathematically there still exists this possibility. In these cases, Simon will recommend further action to the user, like new questions or the use of more tools, in order to break the tie. Remember, the more inputs and quality information you provide to Simon, the better the quality of the analysis will be and the more confident you will feel that you are making the right choice.

Let Simon Decide does not and will not ever tilt the outcome of your decision to serve any brand, product, or institution. Simon is an unbiased resource who does not care what specific alternative you choose, as long as it fits you and your needs. To put it simply, his results cannot be bought.