loss, loss of control in the work-in-process level,
redundant inventory stored as buffer at the point of use
in the plant, missing parts, wrong parts delivered and
excessive inventories (Harris, Harris and Wilson,
2003). In logistics, the achievement of a higher robot
density has at least one additional relevance argument
and one additional criticality. The first is a
demographic component: in industrialized countries,
where quality of life is relatively high, unemployment
rate is low and population is ageing, it is becoming
increasingly hard to find labour willing to take over
ergonomically hard jobs (Abeliansky and Prettner,
2017). The second one is the impossibility of the
customer to perceive any improvement in quality due
to automation. These two argument make it at the same
time more challenging and more necessary to increase
the robot density in logistics, which is a challenge that
especially online wholesalers take really seriously.
Amazon for instance issues every year since 2015 the
“Amazon picking challenge” (Correll et al., 2018) to
stay close to the best basic-research development in
object recognition and grasping for small items of
different nature (Morrison et al., 2018). At the same
time, Amazon deployed the KIVA system on a large
scale in its distribution centres and warehouses. This
automates the transport functionality of the
commissioning process using high performance
available technology, while leaving the unstructured
task of the picking to a human operator (Li, 2016).
Recent research (Bonini and Echelmeyer, 2018;
Bonini, Urru and Echelmeyer, 2019) focuses on
formalizing this empirical process of finding the right
level of automation. Answering in a structured way to
the question “who-does-what” between man and
automation could be the key leading to lean human-
robot interaction, thus increasing the robot density
even in the logistic sector, with a substantial relief for
human operators of ergonomically hard tasks. Using
the structured approach provided by Bonini et al.
(Bonini, Urru and Echelmeyer, 2019), in this paper we
analyse the process of supply of assembly lines,
seeking the most efficient combination of automation
and manual labour, satisfying all stakeholders´
requirements. After a brief summary of the state of the
art for allocation of functionalities between human and
automation, with a specific focus on the Quality
Interaction Function Deployment (QIFD
) method for
lean HRI, we present the scenario and the result of the
application the QIFD, which are then discussed.
2 STATE OF THE ART
As fully autonomous systems are often too expensive
and low performing and simpler cheaper systems are
not enough flexible, Bonini et al. (Bonini, Urru and
Echelmeyer, 2019) proposed to set the focus on using
simpler cheaper systems in interaction with human
operators. If the interaction is well designed, this
could improve costs, performances and acceptance.
In order to find convenient balance between manual
work and automation solutions, first the so-called
“all-or-non-fallacy”, namely the false idea that either
a process should be fully automated, or it should be
fully manual (Sheridan and Verplank, 1978), needs to
be abandoned. This presumes an allocation of
functions among automated and human agents that
can follow several principles, the simplest of which is
the Fitts´ list “Men are better at-Machines are better
at” (MABA-MABA) (Fitts, 1951) updated through
the years as new technologies were released (Price,
1985; Hancock and Scallen, 1998). More elaborated
qualitative and quantitative approaches are those of
the comparative, leftovers and economic allocation
(Rouse, 1991) or the sharing of control (Inagaki,
2003). Most of these methods approach heuristically
the function allocation problem, delivering results
that need to be validated. Others (Ranz, Hummel and
Sihn, 2017) developed analytic approaches aimed to
objectivize the function allocation problem by
seeking an optimal solution. While effective for a
narrow and specific low-level task of the work
breakdown structure, these kind of analytic optimum-
seeking approaches are ill suited for the analysis of a
large process chain, where too many dynamic
parameters come at play. The problem with existing
methods from the literature is that they are either
exclusively qualitative, or, in the effort to quantify the
decision making process, focus on a narrow array of
parameters. For this reason, with the objective of
function allocation in the line supply process, in this
paper we use the alternative approach introduced in
(Bonini and Echelmeyer, 2018) and refined in
(Bonini, Urru and Echelmeyer, 2019), namely a 12-
steps heuristic method that functions as a decisional
support for process design. The method has been
applied in a focus group, where participants had
various competences. The decisional process has
been tracked and documented using the House of
Quality Interaction visual tool. Thanks to the QIFD
method, different automation scenarios were created
and evaluated with respect to their compliancy to two
sets of requirements of all process stakeholders: (1)
hard requirements, representing the view of the
investors and considering parameters such as the need
for automation, efficiency and performance and (2)
soft requirements, representing the view of the
user/partner of the automation, thus considering