like: work task teams.

Células de trabajo / Team work (Trabajo en equipo) Project work team creo qeu sería redundante, pero fijate.- Suerte!

without any context it's difficult to say, but simply 'cells' could fit in just as well as anything else, if the context makes it obvious that the subject is 'work cells'

Another option for you.

Skills can be taught and knowledge acquired, but motivating individuals to produce quality work requires effective management skills within the organization. There are various management models and theories that expound the virtues of role integration, flexible **work groups**, delegation of responsibility and other incentives. These are all aimed at motivating individuals and gaining their commitment to achieving quality goals.
http://www.stcuk.org/newsletters/April2006/quality-strategy....

Plan Development: Task Identification – Work Breakdown Structure
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Identify 5 to 10 major **work groups**, which primarily set up “How” the work is ... quality can be monitored through performance criteria associated with each output ... Departmental – focus is on organizational control of one manager with ...
pd.nottingham.ac.uk/eng/content/download/.../work-breakdown.doc -

[PDF]
Head of Organisational Development
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L4 Make management-control decisions within the work group. B: Effectiveness and accountability. •. L4 Manage work groups to make commercially viable choices; ... leading and managing **work groups** to deliver high-quality results ...
www.christianaid.org.uk/.../Head of organisational developm...

Lean manufacturing - The IET
1 Oct 2008... reducing changeover times, quality control, process capability, .... **Work groups** are transformed into teams. Managers act as leaders. ...
kn.theiet.org › ... › Special reports › Lean manufacturing - Cached -

[PDF]
Organisational Behaviour
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independence and personal control over work. It is a moderating factor which must be ... Brainstorming in **work groups** defers judgement about the quality of ...
https://studentservices.ebsglobal.net/.../h17ob-ob-a3-1-2009... -

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Note added at 18 horas (2010-09-26 17:31:01 GMT)
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Given the additional context I think "WORK/WORKING GROUP" would suit the context well.

Noun 1. working group - a group of people working together temporarily until some goal is achieved; "the working group was supposed to report back in two weeks"
http://www.thefreedictionary.com/working group

work groups
Formal and informal groups in the workplace that collaborate as a team on work tasks, for short or for indefinite periods of time. The quality circles movement makes work groups central to the production system, with responsibility to study and resolve production problems.
http://www.encyclopedia.com/doc/1O88-workgroups.html

Bourton Group: Sustainable performance improvement - Knowledge Centre
A daily communications meeting for each **work group** in front of its ... It can be used to find root causes and to prove benefits of **improvement projects**. ...
www.bourton.co.uk/knowledgecentre/glossaryofterms.html - Cached

Team Business Development is ideally suited for public services cost savings and improvement initiatives. TBD ensures that any new **work group** achieves fast and effective results from change management and improvement programmes.
http://www.teambusinessdevelopment.co.uk/public_sector_share...