<Ul> <Li> Basic cleaning tasks are standardised, with little variation among different enterprises . </Li> <Li> The nature of the job and required standard of performance can be clearly defined and specified in a contract, unlike more technical or professional jobs for which such specification is harder to develop . </Li> <Li> Some organizations prefer to outsource work unrelated to their core business in order to save additional salaries and benefits required to manage the work . </Li> <Li> Some organizations may feel uncomfortable dealing with labour relations related to low wage employees; by outsourcing, these labor relations issues are transferred to a contractor whose staff are comfortable and experienced in dealing with these issues, and their approach can benefit from economies of scale . </Li> <Li> If a janitor is unavailable due to sickness or leave, a contractor which employs many janitors can easily assign a substitute . A small organisation which employs one or a few janitors directly will have much more trouble with this . </Li> </Ul> <Li> Basic cleaning tasks are standardised, with little variation among different enterprises . </Li> <Li> The nature of the job and required standard of performance can be clearly defined and specified in a contract, unlike more technical or professional jobs for which such specification is harder to develop . </Li> <Li> Some organizations prefer to outsource work unrelated to their core business in order to save additional salaries and benefits required to manage the work . </Li>

How many janitors are there in the united states