INGENIEUR
productivity in a construction project and for the
organisation itself.
Waste Generation in the Construction
Industry
Construction contributes a significant amount
of waste and is linked to many environmental
issues. The generation of waste by the industry
needs to be examined by looking into the whole
life cycle of a building – planning, design and
procurement; construction; occupancy; operation
and maintenance; and renovation and demolition.
In this context, managing construction waste
includes: eliminating waste where possible;
minimising waste where feasible; and reusing
materials which might otherwise become waste.
It is envisaged that waste management in the
industry should consider a waste management
hierarchy (Hamid, et. al. 2016). The construction
sector is responsible for about 60% of material
resources taken from nature, 50% of water and
energy consumption, 50% of water pollution, 23%
of air pollution and 50% of total generated waste.
(Abo-Zaid & Othman, 2018).
Statistical data shows 10-30% of waste
generated originates from construction and
demolition works. Urbanisation and rapid
development in this day and age has resulted in
a drastic growth in construction activities and
hence, the amount of construction waste has
increased. The Solid Waste and Public Cleansing
Management Corporation of Malaysia (SWCorp)
estimates that approximately 8 million tonnes of
construction waste per year is generated from
construction projects (Saadi, Ismail, & Alias,
2016). Therefore, waste represents a relatively
high percentage of production costs and
construction waste is one of the major factors
that needs to be taken care of as it will eventually
increase the cost of a project (Mydin, Khor, & Sani,
2014).
Construction Waste Categories
Construction wastes have a greater impact than
labour, parts, supplies and equipment used in
the production process. Waste in construction
projects is defined as anything produced in the
production process that may be considered
damaged or defective and resources produced
which cause direct or indirect costs and do not
add any value to the final product (Abo-Zaid &
Othman, 2018 and Mydin et al., 2014).
The concept of lean management, derived from
the Toyota Production System’s Toyota 3M Model,
defines construction waste in three categories -
Muda, Mura and Muri.
The 3M Model
Muda is a traditional Japanese word meaning
waste arising from an activity that does not add
value in the creation of a product or service for
the customer. Muda costs money, consumes
time and resources but does not add any value
to the finished product. Muda includes non-value
added activities in the production processes that
are necessary for the end customers such as
inspection and safety testing. It also non-value
added activities that are unnecessary for the end
customers which are categorised into seven types
of waste – (1) Transportation, (2) Inventory, (3)
Motion, (4) Waiting, (5) Overproduction, (6) Extra
processing and (7) Defects (Do, 2017).
Mura is the Japanese word for unevenness
or inconsistency. In this context, inconsistent
workloads in production or processing can lead to
employees being overworked or idle and cause an
accumulation of work in process and unnecessary
levels of inventory. Therefore, the presence of
Mura leads to Muda (Kanban Zone, 2019). Mura,
however, can be avoided through Just-In-Time (JIT)
systems. JIT uses the concept of delivering and
producing the right part, in the right amount, and
at the right time. It is a “pull-system” strategy that
limit overproduction and avoid excess inventory.
Muri is the Japanese term for “overburden”.
It exists when people and machines are utilised
12 VOL 82 APRIL-JUNE 2020