In the particular case an employee left due to pregnancy as a reception class teacher. When she returned she was a Year 2 teacher. She took the case to the employment tribunal for not being given the same job.
The school had a policy of moving teachers to different classes every two years, and it was held that on the basis of the nature, capacity and place being the same then it could be considered the same job.
In dealerships and garages it may be that sales staff, technicians, administration staff etc. will raise complaint if they are not in exactly the same post. However, the case does help in arguing that the job is the same. Providing the job title still applies, and the employee has not lost grade or status and it is in the same general place then it is the same job.