The Aymara word ayni designates a service rendered with obligatory repayment of equal kind. The Quechua word mit'a designates a 'turn' of labor and the equal exchange of work. Ayni and mit'a allow a household to temporarily mobilize more labor than that for which it has workers, and this is essential for mountain agropastoralism. An individual's brothers, sisters, their offspring, nieces and nephews, comprise the nucleus of kin with which mit'a and ayni are exchanged for agricultural tasks, for house building, and for other jobs that a couple cannot do alone. Ideally, the type of labor rendered is the same type of labor that will be returned.
Strict accounting is involved.
When male and female kin assemble to execute a job, such as plowing a relative's field, they do not work as a gang. Instead each couple works a different field row and then another. By clearly segmenting work the tasks that kindred render are clearly defined. Subdividing jobs into repetitive, modular tasks also characterizes large undertakings. When a number of ayllu are concerned with common endeavors, such as building churchyard or cemetery walls, each constructs and maintains a specified section.