Alayavijnana parallel or consecutive?

One of the main features of Yogacara School is the doctrine of the eight consciousness (storehouse con. or Alayavijnana). The question is if this consciousness is parallel to other streams of consciousness like a substratum over which other 7 consciousness function or it is something like Bhavanga i.e. when other consciousnesses cease it start its work? In the first case we have two consciousness functioning in every single moment.

store consciousness=buddhist unconscious

I submitted an essay for MAHAYANA BUDDHISM arguing that store consciusness is the Buddhist equivalent of the unconscious as posited by westen psychoanalysts (notably Jung). It's one interpretation among many: people are free to reject it.
I quote from my essay:
If dependent co-arising and intention play center-stage, another choice shall be made about what exactly undergirds the production of intentions for the purpose of understanding the exact dynamics overarching the endless cycle of rebirth, for Buddhism explicitly rejects the notion of soul as posited in Judaeo-Christianity.
Roughly speaking, two options are offered. One is to concoct a Buddhist version of soul (pugdala): a series of theories of rebirth and karma one might call 'punch-card theories'. At the moment of death, each individual is associated with a sort of metaphysical 'punch-card' registering good, bad and neutral deeds in a rigid blueprint for a future existence. The other option we discuss here (store-consciousness) is more subtle in order to account for the endless possibilities behind the rebirth and intention cycle: another form of identification that makes each sentient being unique, but in a flexible way much as fingerprints do.
Vijnana as consciousness ( which Abhidharma uses interchangeably with personality, citta) represents a factor of samsaric existence. It embodies the consciousness that engages in rebirth at conception's time to put in motion the body-mind complex; it persists with it until death, acting then as transmission belt towards another existence. This never-ending stream of consciousness is the necessary medium to transmit karma from life to life: this view came to be associated with Yogacara. The five sense-consciousnesses -along with the superior consciousness that serves as interface1 - shall be posited here, but not examined, for this essay deals mostly with the seventh and eight consciousnesses as mainstays of the 'Buddhist unconscious':
In the case of the sixth cognitive faculty (manas), consciousness itself (i.e., its preceding moment) acts as a faculty for apprehending non-sensuous objects. -...-These samkhára, which through conception (viññána) find continuity in the new life, contain latent in them the anusaya, which is the name for the resultant of all the impressions made on the particular flux (santána) of elements in the whole course of its faring (samsára). It is these latent factors that the psychoanalyst, for instance, finds (Malalasekara 1951:6,11).
The deepest level of consciousness – the store consciousness - is identified by the Buddha as the fourth source of nutriment. We consume much more than edible food. We also consume with our senses, desires and cravings. This consumption then feeds our store consciousness which “eats” everything we put into it. If we fill it full of toxins, violence and other negative energies, then it is this accumulation in our consciousness that then drives us. On the other hand if we feed our consciousness with mindful nutriments, then a different energy occupies the driving seat of our life -...-. This is the energy of mindfulness. (Prattis no date:2).
It is said [AKBh IV 1] that the world in its variety arises from action (karma). It is because of the latent dispositions (anuśaya) that actions accumulate (upacita), but without the latent dispositions [they] are not capable of giving rise to a new existence. Thus, the latent dispositions should be known as the root of existence (mūlaṃbhava). (Waldron n.d:9).
“In other words, the manas is the source of ego-identity.-...-The alaya-vijnana is a subliminal layer of the mind, which is the storehouse containing all the possible seeds of future experiences and the traces of past experiences” (Moon 2012:64).
“Lord, the nescience entrenchment which has existed from beginningless time is unconscious.”2. This entrenchment of nescience also affects all sentients being who have not yet attained full Buddhahood, including arhats and Bodhisattvas. Although the residual amount of nescience in a Bodhisattva is to be considered next to non-existent, it neverthless persists. Nescience is another characteristic of the unconscious as posited in the West:”Jung’s unconscious and Yogacara Buddhism’s alaya-vijnana function as subliminal consciousness. Their characteristics and functions in the relation with cognitive awareness play a key role in the two systems’ ideas of the processes of self-realization.”3. If alaya-vijnana represents a multi-layered4, ebullient “abiding, maturing and accumulating, yet subliminal, level of basal consciousness. ”5, it is clear the 7th and 8th consciousnesses in Yogacara and the unconscious in the West serve roughly the equal purpose of making sense of intentionality as coalescing from a composite, ebullient primordial soup that is hidden, unconscious, on a backdrop of nescience: the greed, hatred, delusion, doubt, sloth and torpor of Buddhism; the instinctual drives of Freudianism. Of course, some even reject this parallel entirely as a (botched) exercise in cultural hegemony on the part of westerners. The present writer, however, still hypothesizes that:”The alaya-vijnana and Jungian unconscious contain not only the traces of personal experiences, but also collective, universal, and impersonal nature of human experience which is universal for all human beings.”6, as Bastian -unknown today but writing years before Jung's birth- had convincingly argued ages ago.


Thank you. So you see it as something parallel always present and functioning.