WEBS (Work Experience in Bochum and Sheffield) is funded by almost 30 companies, individuals and schools. Pupils stay with the families of children from the twin town, and their parents make a voluntary contribution of Pounds 50 towards the cost of the trip.
Since the scheme started five years ago, 40 children have been out to Bochum, working in shops, offices, hotels and banks and looking after young children and animals. Students go to Germany in May or early June, and German children make the return trip in November.
WEBS organiser Phil Porter says the experience has definite benefits: "Most pupils improve their GCSEs by at least one grade - and you notice the difference in their oral exams."
He admits part of the reason for going is to improve their language skills, but the work element makes it much more than a straightforward student exchange. "They are going to be in an adult environment and be treated as an adult."
Mr Porter, an IT teacher at Sheffield's City School until he retired last year, came up with the idea while exchanging e-mails with the Heinrich von Kleist school in Bochum. His suggestion went down well with the German school's head, who chairs the town's education committee.
WEBS' success has prompted plans to expand the scheme, offering places to up to 100 students throughout the city. But Mr Porter says: "One difficultiy is the lack of financial support for pupils of 16 and under." So the school has set up a charitable trust to seek funding.
Eventually Mr Porter hopes the project might take in Sheffield's Russian, French and Spanish twin towns. Meanwhile, this year's scheme will break new ground this summer, when a Sheffield teacher will swap jobs with a German counterpart.