OEE provides a method to monitor the efficiency of your production facility and tracking downtime provides information of where to focus efforts to improve efficiency. Think of it this way, if your production line typically runs at 69% OEE, what actions do you take to increase it? OEE alone doesn't tell you what factors are preventing your efficiency from being higher than 69%.
In the simplest form, downtime tracking will identify the production cell (machine or process) that is preventing your production line from producing product. This can be done manually, but history has shown that manually collected downtime information is inaccurate. In addition, if it is manually collected on paper log sheets, then someone has to further enter the details into a program or spreadsheet to be able to organize it into actionable information used to focus your efforts to make improvements. Putting recording inaccuracies, extra labor and typos aside, by the time the information is available, it is old.
Tracking downtime automatically or semi-automatically solves the issues associated with manual tracking. In a perfect world, monitoring all downtime reasons automatically is the ideal solution. But in the real world, this can be difficult, pricey, or just not practical. For this reason, it is important for downtime tracking software to support an automatic reason detection with a manual override.
For example: if an operator presses the stop button because they see a bottle laying on its side feeding into a filler, then the only automatic reason that can be detected is "operator pressed stop button". Now the operator should be able to override this reason with more specific information.
Once the period of time that production cells were not producing product and the associated reasons are recorded, analyzing the summary of the reasons will identify where effort should be focused to improve efficiency.