on the odd occasion

[Лида]

Контекст:
The Scheduling Problem:
...
· Last but not least are our suppliers, who have been known to deliver late on the odd occasion. When this occurs it requires the planner to re-schedule work that cannot be built but also to bring in work that can be built.

не знаете, нет ли устойчивого перевода?
Это "по непонятным причинам"? по "странным обстоятельствам"?

[Kate_I*]

время от времени (имхо)

[Juliza]

случайным образом
ИМХО

[triplet]

Поддерживаю Kate_I*
Эпизодически, нерегулярно