This style of op is known as 'Sea of Green' or SoG.
You can build this op in any scale you like, from a single mother and just one plant put in to the flowering area every two weeks up to as big as your needs require.
The idea is to grow only the top cola of a naturally growing plant with none of the lower branches and the small buds those branches produce. All branching, pretty much everything on the lower 1/3 of the plant, is snipped off in about wk 2 & 3.
Plant at 6 wks flowering, note lower branching is removed
The method of putting clones in to flower with no vegging time keeps plants relatively short, to about 36-40" (1 metre), which better suits artificial lighting.
Even powerful HPS lighting can only penetrate foliage so deeply, so a metre tall is just about right. I find that big lights give better bud density, so I use two 1000W HPS, one over each pair of 4' x 4' flood trays.
The mums are maintained under 24 hour 400W HPS. The clonebox has 6x 18W fluoro tubes (24"), usually on 24/7 but shut off for the first 6-8 hours after doing a new batch of cuttings.
Clones go straight from the clonebox into the flowering trays- no vegging required. They grow a little bit vegetatively for the first 3-4 weeks but then stop getting taller and start making bud weight after then.
I keep about 6-8 mothers and do about 30 cuttings every 2 weeks from them. I choose the best 20-23 clones to be put in the 4-tray flowering area.
Leftover clones become replacement mothers or are discarded. Mothers are replaced one by one, about every 4-8 weeks as needed.
As each batch of clones goes in to tray #1, a batch comes out of tray #4 to be harvested, every 2 weeks.
The mother vegging area is in the same room with the flowering plants, but has a lightproof curtain to prevent interrupting the flowering plants' lightcycle and has its own ventilation system as well. Each tray in both the veg & flower areas has its own pump, reservoir tank and timer, allowing the watering rate and nute mix to be tailored to the plant for vegging as well as during each 2 week phase of flowering.
See
my gallery for pics of the op in action as well as pix of clones in rockwool cubes and clonebox details.