If you read yesterday's post, you probably know the answer is "It depends." There are certainly some areas of overlap between the two approaches, and some common underlying values. But they're not exactly the same thing. Let's take a look at some of the attributes of these two approaches. Please understand that although I'm taking a somewhat binary approach below, the comparison isn't strictly an either/or in every case.
Lean is a process-oriented methodology.
FIST is a person-centered value set.
Lean is about value-chain efficiency and manufacturing. It values repeatability and focuses on program commonalities.
FIST is about effectiveness and creation. It values originality and emphasizes program uniqueness.
Lean strikes me as potentially introverted, focused on removing waste from processes in order to maximize value for the customer.
FIST is emphatically extroverted, focused on ensuring the capability is "affordable, available and effective." It has a higher tolerance for "waste."
Despite protests to the contrary, Lean strikes me as somewhat myopic - not in theory, but in practice. Lean is supposed to be strategic, but when it's actually implemented, human nature tends to devolve it to narrow applications (i.e. implement a change that saves my unit $10 even though the change costs the overall organization $20).
FIST, on the other hand, is systemic, and takes into consideration the human element of decision making and problem solving.
Lean's focus on removing waste is probably good. Lean's over-definition of waste might also be good. It focuses on optimization
FIST has a tolerance for what Lean calls waste, and maybe even an affection for waste. FIST is not particularly interested in optimization (which it views as impossible anyway). Instead, FIST is about near-term sufficency as a strategic objective. The ability to rapidly deliver a capability for a short/near-term need is itself a strategic capability.
OK, this is just a quick sketch of some differences. Lean and FIST do indeed have some things in common. And Lean has much to commend it, particularly in areas where the work is well-bounded, repeatable, etc. It makes sense to apply Lean to situations like invoicing, manufacturing, maintenance, etc. But in other areas, where the work is not repeatable or well-bounded, the FIST approach can still serve to guide decision making and problem solving.