There's no doubt documentation in the IT field is vital. Often times we work in teams and need to collaborate. At some point there will be turnover, someone will take a vacation, or be out of the office. Unless you want phone calls or emails while you are out of the office, you'll need proper documentation in place.
I feel that documentation should be everyone's responsibility to an extent. For example- If you're a network admin, your desktop and helpdesk support teams need infrastructure documentation. If you are in a desktop or helpdesk support role, you should create documentation on how to install the company applications. Documentation should be treated as ongoing team affair.
In the consulting space there can be a different dynamic. Some of my clients do not have internal IT staff. I am solely responsible for everything related to technology so I create documentation for every aspect of their network. I do this for my clients but it also is for my support staff.
I think anyone reading this or working in IT understands the benefits of having documentation. With that being the case, I can't tell you how many times I inherit a client that has little to no documentation. So many IT departments and consultants get too comfortable with their employer or client and for one reason or another do not create documentation.
My objective in this post is not rant about how no one is documenting their work. I'd like to share my method as a consultant and provide a plan for folks working in an "In house" IT department.
My method is quite simple- Make documentation a priority. The way I do this is I include documentation as a line item in all of my project plans. For example, when I onboard a client, documentation is in the budget. For existing clients when I do an upgrade or install something new, documentation is included in the project plan. This way documentation is in the budget and scope of each project.
If you work in an "In house" IT department, the same thing should be said- Make documentation a priority. Even if you work in a helpdesk or desktop support role, start documenting even small items somewhere like where the print drivers are located. Start a wiki page and update as you roll out new items. You'd be surprised how fast you can build a knowledge base in just a couple of months.