In instances like this, I believe that the best software for the job is going to be ZoneMinder. Using ZoneMinder is a natural fit for the workplace looking to keep things secure with closed circuit video because of the available functionality provided by the software.
Cameras are easily setup to watch the outside building area, monitoring potential problems such as a car prowling. And thanks to the ability to set up pan/tilt, the department in charge of monitoring these cameras can do so with great control. Another benefit that can come into play with ZoneMinder is that you can set up multiple zones per camera. This means that if you need to monitor the area to the side of an entrance area, but would rather not trigger the space where employees are walking in, ZoneMinder's independent zones per camera could be invaluable here.
In addition to ensuring employee safety this can also be used in making sure they're not slacking off. Instead of peeping over their shoulder directly, consider a less intrusive way to do this by using ZoneMinder to monitor breakroom areas.
Regardless of which software solution listed here you choose to add, you'll need to decide whether notifications will be part of the project. Because none of the options listed above include paid monitoring services, any monitoring and response will come from whomever receives the notification that an event has taken place.
Obviously, HEYU doesn't need any notifications. Yet both Motion and ZoneMinder users may benefit from someone being kept in the loop to monitor events taking place. The most common types of notification with motion detection software for Linux include a combination of SMS and email alerts.
What I don't recommend is attaching some loud X10 alarm speaker to such a system. Reasons for avoiding this range from local laws regarding alarm licensing down to annoying anyone within ear shot of a false alarm. My suggestion of using motion detection assumes you're setting this up to better the daytime experience for everyone in the office -- not trying to create the "ultimate burglar alarm."
Why the emphasis on X10 devices?
Throughout this article, I've placed a fair amount of importance on X10 devices for use with software solutions like HEYU. This is due to the widely used nature of the X10 protocol, despite there being other up and coming alternatives. It's also considered to be an open standard.
This prevents any one company from controlling the X10 protocol exclusively. X10 is interesting in that it can use the existing electrical wiring to send data from one device to another. This ability lowers the barrier to entry for both the office and home user.
While X10 works great in the instances I've listed above, I would not suggest it as a replacement for a security system. My reasoning for recommending against X10 and motion detection software for security needs is that, like any DIY office automation setup, it's not without some bugs.
The radio protocol used by X10 is spotty at best and not very reliable, based on my testing. Therefore my recommendation is to stick with using X10 devices that enhance power consumption, as this is not a mission critical service for your workplace.
In other words, you're not going to be dealing with false alarm complaints because the lights failed to turn off on schedule. With an office security system, this might be a very different story.
Is any of this really worth it?
By now the question as to the value of all of this has to be crossing your mind. What's the point of monitoring employee activity, using Linux-powered scheduling for lighting or even bothering with zone security outside of the building?
Simple, it's a matter of encouraging productivity, better energy consumption and safety. If you have an alternative means to gain the same benefits, then by all means embrace it with both arms. My hope is to dispel the myth that this kind of technology will cost the cash-strapped businesses of today thousands of wasted dollars. The truth is, by taking the Linux approach you can avoid dangerous vendor lock-in with "potentially shady" software vendors.
For the money spent -- and assuming you can keep the labor costs down -- I think that using these ideas are financially worth it. At the very least, using HEYU will make sure that the lights have been turned off in the evening. I'd also like to point out that IP cameras and parking lot monitoring is a must have.
As for the productivity side of things, this is an area that's likely to vary depending on the existing office dynamics.