We can draw the following conclusions from the
literature. First, in spite of their dominance in practice,
pickers-to-parts order-picking systems have
received less research attention compared to partsto-
picker order-picking systems. Less than 30 percent
of the about 140 papers we considered concerns
pickers-to-part order-picking systems. The reasons
for this may have something to do with the complexity
and diversity of picker-to-parts order-picking
systems. Furthermore, parts-to-picker systems
are often fully or partly automated, thus catch the
attention of researchers.
Second, although the number of publications in
the areas of layout, batching, zoning, storage strategies
(like forward–reserve allocation, family grouping,
and dynamic storage), and accumulation and
sorting is still limited, their number is growing.
Particularly, the areas of storage assignment and
routing appear to have matured the last decade.
Few authors address combinations of the decision