Conceptual System Design and the Human Role

Function allocation: algorithm, alchemy or apostasy?

“…He seems to agree with Jordan when he points out that human performance and machine performance are not a zero-sum game, implying that the combination can be much better that either by itself. Kantowitz and Sorkin (1987) and Price (1990) provide reviews of the earlier literature in function allocation. Hancock and Scallen (1996) also have emphasized that the challenging tasks of today are dynamic, and hence the allocation must be dynamic.…”

The fiction of function allocation, revisited

“…It weds the notorious man}machine dualism to the consideration of design options, while at the same time eschewing design details. Since &&there is no such thing as an unmanned system'' (Price, 1990), FA is thus both an ultimate and unconstrained explanation for design that wanders freely (if not always accountably) between di!erent meanings: thus ironic that the formal allocation process has been rei"ed in the name of integration, i.e. by the systems approach to design.…”

“…&&Some progress was achieved in the '60s and '70s as evidenced by the requirement for de"ning and allocating system functions in a Department of Defense speci"cation, now MIL-H-46855B, Human Engineering Requirements for Military Systems, Equipment and Facilities 2 '' (Price, 1985) But, recalling the aforementioned methodological caveats, one might ask whether such allocation requirements were premature, rather than progressive. Indeed, only three years earlier, a literature survey for the US Nuclear Regulatory Commission (NRC) noted a basic lack of FA progress, in terms of the same requirements:…”

“…Task analysis (the essential human factors method) clearly presumes some representation of the operated system as input to the analysis. In contrast to FA, which aims to &&keep the solutions at bay'' (Price, 1985), task analysis seeks engagement with low-level details and structural particulars. A task, as opposed to a function, is a manageable unit, a pragmatic and action-oriented unit; indeed, to allocate speci,c tasks is a natural human activity.…”