Any data analysis depends on the quality of the data itself so the first step would be to figure out what you want to get out of the analysis. Then design your data entry system so that there is minimal opportunity for mis-entry. If you want to classify different types of incident and injury/harm it is essential that your definitions are very clear and that those doping the reporting/entry fully understand the categories. If you are a large enough organisation you may wish to consider departments, shifts, activities. The list can be endless. BUT, remember those doing the entries - they will get very fed up if it takes ages to record a broken fingernail!

There is software you can purchase which will help in reporting, investigating, corrective actions and categorisation of accidents and incidents. As a rule I'm not keen on h&s software, but due to the complexity of this subject using software might be the answer.

thankyyou

No one has mentioned 'potential'. It's a good idea to record 'reasonable worst case potential' in some way, i.e. how lucky was the organisation in this case. You can record both how severe an injury could have been and also how many other people are exposed to similar hazards. Doing so not only helps you to focus investigation effort on those events with the highest potential for harm, but also provides trend data to show whether you re getting better at controlling your most significant hazards.