Succession sowing/planting?

At risk of boring you, I follow the Roots, Shoots, Fruits and Leaves sowing plan, which means that I sow the same type of things every 4th week.
In Roots week, I sow carrots, beetroot and radish, usually all year round - in the GH or in pots in the cold months and outdoors in spring.
Shoots week is onions, leeks and for things with funny names - like the Oriental veg.
Fruits are peas, beans, tomatoes, cucumbers, courgettes .....
Leaves are lettuce, brassicas and any other leafy things.

Basically, the edible part of the plant dictates which week it falls into.
Once I've sown some seeds from a packet, the remaining seeds go in a Box, ready for the next 4 week session. I stretch the recommended sowing times usually by a month ahead and a month afterwards - if it works, great, if it doesn't, I try again 4 weeks later.

I vary the varieties to match the seasons - like brassicas for spring, summer and autumn.