An assumed and an unthought-of answer to the question would be an easy yes. How difficult could maintaining a notebook register be? If you want an honest answer, then please ask your security guards or even better, take the budget of your manual visitor management system and compare it with a company that has digital visitor management system.
But for now, let's list out as many reasons as to why using manual register is not as easy as you think.
Time consuming sign-in process
Long-lines are a primary source of frustration. Entering details in a logbook with a pen can be super irritating if you're in a hurry. A visitor has to fill out details that provide a record of the visitor's stay, including such details as name, company (when appropriate), the date, time in, time out, and destination (a person, floor, or room number) and that in any perfect world will take time.
Illegibility of handwriting
As aforementioned, if the visitor is in a hurry like attending an interview and have seconds left before it starts, then taking that pen and writing down those details can be a Himalayan task. Even otherwise, logging in with a pen is a tedious work that will get boring after the first few times. Upon which, it becomes a chore that the visitor needs to do to get to the next step. Therefore, expecting legible handwriting from a visitor is as hopeless as expecting sand to turn into gold.
Extra staff cost
Computer as a machine reduces human effort. In place of 20 security guards, you can employ two and give them a computer. They can do the same work but with maximum efficiency and in lesser time. Use computer; it is one of the greatest inventions in the history of mankind.
Potential security risk
The potential for security compromise with manual registers is super high compared to digital visitor management system.
Take for instance; most of the entries in manual registers are done in illegible handwriting. For all intent and purpose, one can easily use this loophole to register under a different name. If you want a criminal to enter your facility, at least make it tough for him. Manipulating data with manual registers is easy.
Also, a notebook, however big it is, can only accommodate so much of data in one single page and even with two pages combined. (I'm taking two pages because anything more than that (turning pages) will pave way for confusion while entering data). And in these two pages, you can draw columns for a limited number to fill out information like name, company (when appropriate), the date, time in, time out, destination (a person, floor, or room number), and the purpose of visit. Even to do this, the register must cram the columns. So assume you have to add another column like material incoming or what the visitor is carrying (like a laptop), what will you do? Probably make another notebook for that. Shoving the visitor with multiple notebooks to fill out information will only look unprofessional.
Retrieving old data
What if your facility faces an emergency situation and you are forced to retrieve old files from ten years back to neutralize it. And what if it has to happen immediately? Would you have the patience to go through and find that particular information from 100s of notebooks with illegible handwriting and torn papers? I guess not. With digital information, retrieving take only seconds, literally.
If you're an administrator of a facility that houses multiple tenants, then keeping away information regarding the visitors of the tenants from other visitors becomes a big pain.
It is a foregone conclusion that humans are receptive to committing mistakes. With manual systems the level of service is dependent on individuals and this puts a requirement on management to run training continuously for staff to keep them motivated and to ensure they are following the correct procedures. Even then, there is no guarantee the process will be error free. Besides, as mentioned earlier in this post, it costs a lot for staff training. Switch to digital.
A lack of quick response
There are limitations to manual registers. It has only one purpose, but an automated digital register can provide a holistic solution to visitor experience. With manual register, you can only details and if there are some discrepancies or doubts, one have to contact the relevant person inside the building either through phone or an email.
I believe I should stop here. But this doesn't mean I'm concluding the topic. As someone who have been in visitor management industry for a very long time, I understand that there are more points to be covered and even some of the points listed out like security risks of manual registers needs a blog post of its own.