I'm currently reading a book about "systems thinking" for a doctoral class. Having been a manager, and currently being a programs director, this is a helpful book and way of thinking. As a brief aside, I'd describe it as the combination of Stoic non-reactiveness, Family Systems psychology, and the Christian goal of eusebia from a business and industry standpoint: fascinating. Being involved in the various disciplines of academic theology, I'm inclined to try and apply some of what I'm learning to those fields as well.
Systematics, almost painfully obvious, is the field most like the thinking engendered by systems theory. After all, systematics is about finding (or generating) the system that holds all the disparate parts of theology together so that they might find proper pastoral application. Biblical Studies, of course, is a foundation piece to this, as well as Historical Theology and Dogmatics (yes, Dogmatics, the study of the Church's understanding of theology, is different from Systematics: their confusion in the Protestant world is bizarre); canonical criticism, text criticism, the higher criticisms, biblical theology, narrative theology, and so on are all to be placed together in a workable system for use in "training in righteousness," etc.
However, as is well known, there are deep divides in the theological disciplines: biblical studies folks don't get along well with historians (either church historians or historical theologians); pastoral theology sees little need for the erudition and aridity of systematicians; dogmatists find biblical studies to be too concerned with the ancient Near East to be helpful in the life of the church today. And so on. Somewhere there has developed a feedback loop that continues and magnifies these unhelpful practices, assumptions, and habits. (One of the things the systems thinking textbook says is to avoid placing blame, for that means we are not being rightly critical of our own place inside the larger system; however, in this case, it seems okay to me to blame the Enlightenment).
What if, instead, the work of a systematician was to identify how all the pieces fit together in a whole? A whole, that is, that works properly: disciples are formed. A systematician, then, is not the same as a philosophical theologian (although we need those too); they are the ones who study the whole breadth and depth of all the theological fields to pull together and integrate the seemingly disparate parts. They are the mediators of conversation between those who would say that the "original authorial intent" is the key to biblical hermeneutics and those who argue that it is the use in the Church throughout time that demarcates meaning; between those who see ethics as a philosophical endeavor and those who deal with the practical effects of seeking holiness at the parish level; and so on.
This is only a brief foray into systems thinking in theology. Currently I still know precious little about it (you can decide what the antecedent to that is).