Environmental Engineering Reference
In-Depth Information
Table 5.3
Example of check sheet showing problems collected during the
course of several weeks on a hypothetical fruits and vegetables processing facility.
Problem
Day
Mon
Tue
Wed
Thu
Fri
Total
Leaking equipment
/ / / /
/ /
/ / / /
/ /
/ / / /
18
Dirty raw material
/ / /
/ / / /
/
/ / /
12
Equipment failure
/
/
/ /
/ /
6
Error in formulation
/ /
/ /
/ / /
/ /
9
Total
11
10
7
5
12
45
Adapted from ASQ Quality Tools.
LEAN MANUFACTURING AND SUSTAINABILITY
The principles of lean manufacturing are one of the most significant tools for efficiency
improvement. The modern version of this management concept was initially developed by the car
manufacturing industry; however, it can be applied to any enterprise including the food industry.
The focus of lean manufacturing, or lean, is the elimination of waste, which is defined as
nonvalue-added activities, thus improving efficiency and value added. Nonvalue-added activities
are actions that consume resources but do not contribute to the product or the business profits. In
other words, it is something the customer would not be willing to pay for.
From the sustainability point of view, these wastes are associated with useless consumption
of energy, water, and nonrenewable materials while increasing the need of disposal of products,
unused or spoiled raw materials, and wastewater.
The main wastes targeted by lean are as follows:
1. Overproduction.
2. Waiting.
3. Unnecessary transportation (of material).
4. Waste of the process itself.
5. Excess inventory.
6.
Motion (of people).
7.
Correction of defects (scrap, rework and inspection) (Levinson and Rerick, 2002).
Overproduction is a frequent offense in food manufacturing, especially because food
products are either perishable or their quality attributes are significantly altered with time.
Overproduction means producing more, earlier, or faster than is needed by the customer or the
next step in the production process. Consequences of overproduction are excess inventory,
poor quality, increased labor cost, extra storage and transportation, impediment of a smooth
flow of materials, and waste of leftover product. Some reasons of overproduction are lack or
reliability in the processing facility and in the supply chain, poor forecasting of the demand,
unbalanced production system, and poor scheduling.
Waiting can be the result of many causes like inadequate scheduling and planning, poor
maintenance, unbalanced process layout, and so on. Besides the cost associated with idle
operators, waiting causes waste of energy in the form of heat, cold, and mechanical energy
from equipment running idle.
Unnecessary transportation of material is the result of inefficient plant or storage facility
layout or inadequate planning. The outcome is waste of money, time, energy, and possible
