Once a plant has finished installing a data collection system, the next question is usually not about data. It is about screens. Maintenance wants to see the values that are going wrong. Production wants the running total for this shift. Management wants the whole plant on one screen.

In most factories the data already exists. Voltage is on the meter display, temperature is on the machine panel, and the running status sits inside the control cabinet. The problem is not a lack of data. It is that the data sits in separate places, has to be read one point at a time, and when something happens at two in the morning nobody can say how the values were moving beforehand.