I have been using it for many years. I have been using it for five years in different domains. 

I have been using the solution for two years.

I have been using IBM Rational DOORS for four or five years. I work as a SI in my company. Also, I don't remember the version of the solution I am using.

I have worked with IBM Rational DOORS for one and a half years.

We are using version 9.7.

The latest version is next generation and we don't use it.

I have been using this solution for six months. 

I have been using IBM Rational DOORS for a couple of years. We are using both V9.5 and V9.7 of the solution.

I've been using the solution for four years. 

I have been using IBM Rational DOORS for about four years.

I've been using it for around 10 years since 2006. I was responsible for deploying it, including defining data models, training teams, and administrating the database for two different organisations. Both organisations are worldwide, and In the second, the user community was over 400 people worldwide.

I have been using DOORS for 15 years, 1st two as a software developer that looked up the requirements for the GUI he was assigned to develop, the latter 13 for everything from writing DXL to meeting with clients, being a technical lead for a distributed set of DXL developers = lots of fun.

We have been using DOORS for many years, since about 2000.

I've been using the solution for one year. 

I began using this solution in 2000. I used it at my old company; I don't use it anymore.

I used this product up until three months ago. I have been with this company since February.

I've been using Rational DOORS off and on since 2001.

I used the tool for two years.

I have been using IBM Rational DOORS for the past ten years.

I have been using IBM Rational DOORS for approximately four years.

I have used IBM Rational DOORS for approximately 20 years.

I have been using and administrating DOORS since 1998 in multiple different roles, including in Systems Integration, Requirements Management, as well as Engineering Tool Support team member. I've also used v4.0.4, v4.1.4, v6.0 SR1, and v8.3 for requirements management and risk management for medical device development and on-market support.

I used Rational DOORS for approximately nine months during 2014 on a fairly consistent basis.

I have been using this solution on and off for about eight years.

I have been working with this solution for seven or eight years at this point. It's been a while.

I've used it for 10 years.

I have been working with this product since Version 0.1. More than 20 years.  

I've used it for 18 years.

I have been using IBM Rational DOORS for about ten years.

I have used DOORS since 2000 from version 5.4 to 9.6

I have been working on this for almost three and a half years in parallel to other IBM Rational tools.

I’ve used it for one year.

I started using it at v5.2.

I have been using IBM Rational DOORS since 1999, version 0.1.

I've been using the solution for about two and a half years so far.

I've used Rational DOORS since 2009, and v9.56 for 18 months.

I've been using Rational DOORS for over ten years.

I've used it for six months.

I've used it for 12 years.

Actively, I would say three years and non-actively, maybe five years. I was working in the QA department, and I was reviewing and validating the main equipment with IBM Rational DOORS. So, I know the tool, but it took a bit longer before I start to work much more actively with IBM Rational DOORS.

I am not using this product at my current company, but I probably have approximately 20 years of experience using DOORS (Dynamic Object Oriented Requirements System).  

I've been using it for 15 years, and am also using it alongside Rational DOORS Next Generation 6.0.

I have been using IBM Rational DOORS for more than ten years.

I've used it for 12 years.

I've used it for six years.

I used it last year, for one year.