Pie Charts might seem very simple and straightforward, but it can actually be very difficult to use them effectively on a dashboard. On your display surface, whether it be a computer screen or a projection, you are limited by size constraints. There is a certain minimal limit to the sizes of pie chart segments, otherwise they will become so small as to be indistinguishable from each other. Therefore a pie chart is limited to simplistic data sets only. In general, they are only really effective if they are limited to a maximum of five segments.
Based on this, it is natural to ask what exactly it is that pie charts are useful for. If you have too much data then a pie chart is not feasible, and if you must keep your data to a minimal amount why not simply use a table instead? However pie charts are very useful in certain cases. For example, if you wish to generate a straightforward visual display illustrating how monthly expenses were divided within an organisation, a pie chart could be just what you need. It is important to remember however that you should never use pie chart segments comparatively.
When generating a pie chart, always choose colours that are very easily distinguished from each other. In other words, never put two shades of blue side by side, as it will be difficult to tell where each segment begins and ends. Do not randomly place your segments inside the pie chart. The first segment should start at what would be 12 on a clock face. You should then lay out your segments in order, starting form the biggest to the smallest. However, if there is some other meaningful order that can be applied, it is better to use this. Finally if you have a 'miscellaneous' or 'other' segment, do not put this in the most eye-catching colour. This segment is an afterthought, of randomly assembled items that are not significant enough to merit their own segment. They should therefore be shaded a neutral colour, such as grey.