Relay logic was introduced with factory electrification, which underwent rapid adaption from 1900 though the 1920s. Central electric power stations were also undergoing rapid growth and operation of new high pressure boilers, steam turbines and electrical substations created a large demand for instruments and controls. Central control rooms became common in the 1920s, but as late as the early 1930s, most process control was on-off. Operators typically monitored charts drawn by recorders that plotted data from instruments. To make corrections, operators manually opened or closed valves or turned switches on or off. Control rooms also used color coded lights to send signals to workers in the plant to manually make certain changes.
For very simple software, the bug reports might be tracked with sticky notes or spreadsheets. But when the software is more complex, these become unwieldy, and companies need to turn to software designed for the task. Typically, professional bug trackers report on bug severity, priority, when the defect was discovered, exact reproduction steps, who fixed it, what build it was fixed in, as well as searching and tagging mechanisms to simplify finding a defect. These tools don't just assist programmers and project managers; customer service and existing users can use these tools to find out if an issue is known, if it is scheduled for fixing, escalating known issues and entering unknown ones. Bug tracking tools can also help with the workflow, because bugs can be assigned to programmers, then to testers to recheck, then marked to be deployed, and then, after the release, marked as deployed.
A business process management system is quite different from BPA. However, it is possible to build automation on the back of a BPM implementation. The actual tools to achieve this vary, from writing custom application code to using specialist BPA tools. The advantages and disadvantages of this approach are inextricably linked – the BPM implementation provides an architecture for all processes in the business to be mapped, but this in itself delays the automation of individual processes and so benefits may be lost in the meantime.