Labor intensive has a variety of meanings. The most basic meaning is that a specific job is hard, often physical, work. The other two common meanings are found in business situations. The first is that the amount of capitol put into the labor force exceeds the capitol put into any other area. The other common meaning is that the amount of time spent performing an action exceeds the amount of time preparing for or dealing with the results of said action.
The basic meaning of labor intensive, that a job is mostly made up of physical work, is common outside the business world. This meaning, though very common, is also highly subjective. One person will see a job as very physical, while another may not. As a result, the term has a loose meaning that is hard to quantify.
The other meanings of the labor intensive have a much more business-specific meaning. These meanings center around defining the amount of labor put into a job verses the amount of time or money. In either case, these uses of labor intensive contain quantifiable variables.
This first common meaning has to do with money versus labor. In this case, a labor intensive process is any time the money spent on labor is equal to more than half of the money spent on the project or more than the money spent on any other area of the project. Essentially, intensive in this meaning relates to the money spent rather than the difficulty of the work.
The other common meaning relates to time. With this meaning of labor intensive, the amount of time doing a job is greater than the amount of time it takes to set up the job or process the results of the job. This case relates more to individual tasks than the other meanings. While an entire job may be difficult to quantify using this meaning, individual tasks are very easy.
As an example, consider a person working in an office researching new products. While it is nearly impossible to quantify his job as a whole, individual tasks are more simple. If the task being assessed is presenting a product at a meeting, then he may need to prepare a presentation, find updated specifications for his product and make copies for other people at the meeting. After the presentation, he may need to answer several questions.
The results of the example would be easy in real life. The man may spend several hours getting ready for the meeting and a few minutes afterward answering questions. The presentation itself may only be 15 minutes. In this case, preparing for and dealing with the results of the task took much longer than executing the task. So, when seen in this perspective, presenting his product was not labor intensive, although preparing for the presentation most likely was.