March 30, 2017

Developments in Operations Technology - Review Notes

Operations Technology Chapter from Chase Aquilano Jacobs Book

Much of the recent growth in productivity has come from the application of operations technology. In services this comes primarily from soft technology—information processing. In manufacturing it comes from a combination of soft and hard (machine) technologies.

Development in Technologies

Hardware technology developments  have generally resulted in greater automation of processes. Labor-intensive tasks originally performed by humans are getting more and more automated. Examples of these hardware technologies are numerically controlled machine tools, machining centers, industrial robots, automated materials handling systems, and flexible manufacturing
systems. These are all computer-controlled equipments and machines  that can be used in the manufacturing of products.

Software-based technologies are being used in the design of manufactured products and in
the analysis and planning of manufacturing activities. These technologies include computer aided design and automated manufacturing planning and control systems.

Hardware Systems

Numerically controlled (NC) machines are comprised of (1) machine tool used to turn, drill, or grind different types of parts and (2) a computer that controls the sequence of processes performed by the machine. NC machines are now in use many industries. In more recent models, feedback control loops determine the position of the machine tooling during the work, constantly compare the actual location with the programmed location, and correct as needed. This is often called adaptive control.

Machining centers represent an increased level of automation and complexity relative to
NC machines. Machining centers not only provide automatic control of a machine, they
may also carry many tools that can be automatically changed depending on the tool required
for each operation. In addition, a single machine may be equipped with a shuttle system so
that a finished part can be unloaded and an unfinished part loaded while the machine is
working on a part.

Industrial robots are now used as substitutes for workers for many repetitive manual activities
and tasks that are dangerous, dirty, or dull. A robot is a programmable, multifunctional
machine that may be equipped with an end effector. Examples of end effectors include a
gripper to pick things up, or a tool such as a wrench, a welder, or a paint sprayer.  Advanced capabilities have been designed into robots to allow vision, tactile sensing, and hand-to-hand coordination. In addition, some models can be “taught”a sequence of motions in a three-dimensional pattern. As a worker moves the end of the robot arm through the required motions, the robot records this pattern in its memory and repeats it on command.

Automated materials handing (AMH) systems improve efficiency of transportation, storage, and retrieval of materials. Examples are computerized conveyors and automated storage
and retrieval systems (AS/RS) in which computers direct automatic loaders to pick and place
items. Automated guided vehicle (AGV) systems use embeddedfloor wires to direct driverless vehicles to various locations in the plant. Benefits of AMH systems include quicker
material movement, lower inventories and storage space, reduced product damage, and
higher labor productivity.

The individual pieces of automation can be combined to form manufacturing cells or
even completeflexible manufacturing systems (FMS).A manufacturing cell might consist
of a robot and a machining center. The robot could be programmed to automatically insert
and remove parts from the machining center, thus allowing unattended operation. An FMS
is a totally automated manufacturing system that consists of machining centers with automated loading and unloading of parts, an automated guided vehicle system for moving parts
between machines, and other automated elements to allow unattended production of parts.
In an FMS, a comprehensive computer control system is used to run the entire system.

A FMS is in operation in the Cincinnati Milacron facility in Mt. Orab, Ohio, for over 20 years. In this system, parts are loaded onto standardized fixtures (these are called “risers”), which are mounted
on pallets that can be moved by the AGVs. Workers load and unload tools and parts onto
the standardized fixtures at the workstations shown on the right side of the diagram. Most
of this loading and unloading is done during a single shift. The system can operate virtually
unattended for the other two shifts each day.  The system is capable of producing hundreds of different parts.

Software Systems Computer-aided design (CAD) is an approach to product and
process design that utilizes the power of the computer. CAD covers several automated technologies, such ascomputer graphics to examine the visual characteristics of a product and
computer-aided engineering (CAE )to evaluate its engineering characteristics. Rubbermaid
used CAD to refine dimensions of its Tote Wheels to meet airline requirements for checked
baggage. CAD also includes technologies associated with the manufacturing process design, referred to as computer-aided process planning (CAPP).CAPP is used to design the
computer part programs that serve as instructions to computer-controlled machine tools,
and to design the programs used to sequence parts through the machine centers and other
processes (such as the washing and inspection) needed to complete the part. These programs
are referred to as process plans. Sophisticated CAD systems are also able to do on-screen
tests, replacing the early phases of prototype testing and modification.

CAD has been used to design everything from computer chips to potato chips. Frito-Lay,
for example, used CAD to design its O’Grady’s double-density, ruffled potato chip. The problem in designing such a chip is that if it is cut improperly, it may be burned on the outside
and soggy on the inside, be too brittle (and shatter when placed in the bag), or display other
characteristics that make it unworthy for, say, a guacamole dip. However, through the use
of CAD, the proper angle and number of ruffles were determined mathematically; the
O’Grady’s model passed its stress test in the infamous Frito-Lay“crusher”and made it to
your grocer’s shelf.

CAD is now being used to custom design swimsuits. Measurements of the wearer are fed
into the CAD program, along with the style of suit desired. Working with the customer, the
designer modifies the suit design as it appears on a human-form drawing on the computer
screen. Once the design is decided upon, the computer prints out a pattern, and the suit is
cut and sewn on the spot.

Automated manufacturing planning and control systems (MP&CS)are simply computerbased information systems that help plan, schedule, and monitor a manufacturing operation.
They obtain information from the factory floor continuously about work status, material
arrivals, and so on, and they release production and purchase orders. Sophisticated manufacturing and planning control systems include order-entry processing, shop-floor control,
purchasing, and cost accounting.


All of these automation technologies are brought together under computer-integrated manufacturing (CIM). CIM is the automated version of the manufacturing process, where the three
major manufacturing functions—product and process design, planning and control, and the
manufacturing process itself—are replaced by the automated technologies just described. Further, the traditional integration mechanisms of oral and written communication are replaced
by computer technology. Such highly automated and integrated manufacturing also goes
under other names:total factory automation and the factory of the future.
All of the CIM technologies are tied together using a network and integrated database. For
instance, data integration allows CAD systems to be linked to computer-aided manufacturing (CAM),which consists of numerical-control parts programs; and the manufacturing planning and control system can be linked to the automated material handling systems to facilitate
parts pick list generation. Thus, in a fully integrated system, the areas of design, testing, fabrication, assembly, inspection, and material handling are not only automated but also integrated with each other and with the manufacturing planning and scheduling function.

An early adopter of a new technology has the benefit of being ahead of the competition, but
he or she also runs the risk of acquiring an untested technology whose problems could disrupt
the firm’s operations. There is also the risk of obsolescence, especially with electronics-based
technologies where change is rapid and when the fixed cost of acquiring new technologies or
the cost of upgrades is high. Also, alternative technologies may become more cost-effective
in the future, negating the benefits of a technology today.

There could also be risks in applying a new technology to a firm’s operations. Installation
of a new technology generally results in significant disruptions, at least in the short run, in
the form of plantwide reorganization, retraining, and so on. Further risks are due to the delays and errors introduced in the production process and the uncertain and sudden demands
on various resources.

Firms may lack the organizational culture and top management commitment required to
absorb the short-term disruptions and uncertainties associated with adopting a new technology. In such organizations, there is a risk that the firm’s employees or managers may
quickly abandon the technology when there are short-term failures or will avoid major
changes by simply automating the firm’s old, inefficient process and therefore not obtain
the benefits of the new technology.

In many cases, a firm may invest in a particular technology only to discover a few years
later that changes in some environmental or market factors make the investment worthless.
For instance, in environmental issues auto firms have been reluctant to invest in technology
for making electric cars because they are uncertain about future emission standards of state
and federal governments, the potential for decreasing emissions from gasoline-based cars,
and the potential for significant improvements in battery technology.

One more revision of the writeup has to be made.

Full material from the book

Updated  2 April 2017, 9 December 2011

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