Process control is too large an area to make any definitive statement.
In general and to the point of control, Access is not suitable.
If we can break the question down to monitoring a process the answer is probably no.
If we can reduce the question to reporting on a process the answer is yes.
In their simplest form…
Control:
defined as a process input, algorithm and direct process output in a continuous loop in real time.
Monitoring:
defined as a process input, algorithm and output to something other than the direct process in a continuous loop in real time.
Reporting:
defined as using already gathered data, algorithm and output to human users not in a continuous loop and not in real time.
The definitions of control and monitoring may not be strictly correct and in fact may overlap in many cases.
Monitoring, for example, may simply be an alarm condition which is output to human users but does not directly affect the process. If the monitoring produces a process trip then it should be regarded as a control not a monitor. On the other hand, monitoring may involve taking time based analytical samples of the process and adjusting process setpoints to effect the process. This latter description of monitoring the process does not directly affect the process because, if the monitoring stops, the process should use the last setpoint supplied. (Jargon, but the process flunks to the last known valid setpoint. Even down to a thermocouple junction this may apply. Most thermocouple inputs have an upscale or downscale burnout setting. If three thermocouple inputs are feed to a median selector then the correct temperature can still be used even under a single fault condition.)
The point is, though, that reporting is not required in real time and indeed has no direct connection to the process, read or write.
I think it is important to understand something about Access here. Access is not a stand alone program; it is running under what may very well be described as a dirty environment. People may have Word, Excel, Outlook, Internet Explorer and many other programs the user may have downloaded and have open at the same time.
Who really knows under what environment Access may be running? Without the knowledge of the environment, I think it best to assume that Access is running dirty. This is in no way a fault of Access or even Microsoft; it is a fault of the openness of the system.
So, to use Access for process control or monitoring, no.
To use Access for process reporting, yes and I have on two different jobs.
Chris.