||Ex-SE: Expert System on Systems Engineering
Develop Manufacturing Plan
(Manufacturing Strategy / Procedures)
Manufacturing planning activities should not occur in a vacuum. The
manufacturing plan is a plan of action that must be consistent with both the
manufacturing strategy and corporate strategy. A manufacturing plan ensures
thorough planning for manufacture of the system to be produced. It documents
the planning process sufficiently to enable review and traceability. Companies
should apply the planning process iteratively throughout the life of the
The manufacturing plan is the compilation of those documents a contractor
uses to plan and manage their manufacturing effort. (DI-MISC-80074,
Manufacturing Plan, June 30, 1986 p. 1.)
A manufacturing plan provides the means to link manufacturing strategies to
business goals and to measure the progress in achieving these goals,
through:(Danzyger, Howard. "Strategic Manufacturing Plan? Your Competitiveness
Depends on It." Industrial Engineering. February 1990, p. 19.)
translation of business goals into quantifiable manufacturing
development of manufacturing concepts for operations, organization,
equipment, product, facility, and information systems to meet manufacturing
definition of tactical programs necessary to implement manufacturing
construction of an implementation plan to manage
tactical programs and measure progress in achieving business
When Does Manufacturing Planning Begin?
Manufacturing planning activities should follow a logical, iterative
progression that starts as early as possible and results in the issuance of
the manufacturing plan itself. However, it must be stressed that the
manufacturing plan remains a living document.
Manufacturing planning begins in some form as soon as an opportunity is
identified. Once the company decides to bid on a project, the development of a
manufacturing plan should begin in earnest.
Concepts such as concurrent engineering, total quality management (TQM),
and producibility engineering and planning (PEP) all emphasize the early
involvement of manufacturing in the development process. The Front End Process
reference guide, Design Policy, Process and Analysis reference guide, and
Design Reviews reference guide address these concepts in greater detail. In
addition, design reviews play a major role in assessing a product's production
Manufacturing Plan in Perspective
Manufacturing process planning and design is part of an overall concurrent
engineering approach. It is important to understand how the manufacturing plan
fits into the bigger picture. The manufacturing plan is closely linked with
several other areas and plans for a given program. Some examples of program
plans that are either influenced by, or influence the manufacturing plan
statement of work (SOW) and contract data requirements list (CDRL)
work breakdown structure (WBS)
systems engineering management plan (SEMP)
configuration management plan (CMP)
risk management plan
master test and evaluation plan (MTEP)
To make a program successful transition across all phases of development,
there must be connectivity and feedback between all disciplines. Concurrent
engineering philosophies dictate a multifunctional, integrated approach to
development of products and processes. Plans are intended to guide activities
and measure progress.
The configuration management plan describes the methodology and system
which allows for the integration of efforts to proceed in an organized,
reasonable fashion. The transition plan is the road map: the set of directions
which provide structure to the program's life cycle.
It is critical that the planning efforts be dynamic. When any given plan is
written once, regardless of the development phase, greatly increases the
probability of failure. Plans need to be living; they must constantly be re-
evaluated to reflect the current state of affairs and to address opportunities
Manufacturing management has been defined as:
"The techniques of planning, organizing, directing, coordinating, and
controlling the use of people, money, materials, equipment, methods and
processes, and facilities to manufacture systems." (MIL-STD-1528A,
Manufacturing Management Program, September 9, 1986, p. 3.)
In the Manufacturing Management Officer's Handbook, the challenge facing
Manufacturing Officers was to identify their responsibility to the project's
Program Manager with the following objective in mind:
Try to minimize and clearly identify all the risk associated with the
manufacture and production of a system. (Dwyer, James P., Major, USAF, The
Manufacturing Management Officer's Handbook, Air Command and Staff College
Report 85-0730, Maxwell AFB, AL : ACSC/EDCC, April 1985, p. 4.)
This objective can only succeed if the customer and contractor are able to
work together as partners, and not adversaries. Additionally, identifying and
minimizing risk should be a concern for all people involved with all phases of
Often, in the case of such items as the WBS, there is an emphasis on
discrete tasks and items rather than the process. In order to properly manage
the manufacturing planning activities, a manufacturing management system needs
to be in place.
Issues Facing Manufacturing Management
A study conducted by the Manufacturing Management Council of the Society of
Manufacturing Engineers concluded that there are six critical issues facing
manufacturing management that managers must understand if they are to initiate
change in their organizations. The issues identified by SME are:(Veilleux,
Raymond F. and Petro, Louis W., Tool and Manufacturing Engineers Handbook,
Volume 5: Manufacturing Management, Dearborn, MI: SME, 1988, pp.
Operations and Strategic Planning: This involves concentrating efforts and
resources to find the right things to do. Included in these tasks are
planning, management control, planning and analyzing investments, and cost
estimating and control.
Leadership Skills: Managers must develop and upgrade their leadership
skills in order to properly understand the importance and communication of the
company's philosophies and cultures.
People: Managers must aid in the development and coordination of their most
valuable resource - the workforce. Other related concerns in this area include
labor relations and occupational safety and health concerns.
Manufacturing's Function: The manufacturing function needs to be a
management partner with other functions such as engineering, finance, and
marketing. Manufacturing needs to be involved with design and standards
efforts. Additionally, manufacturing managers need to understand the roles of
manufacturing, in relation to such things as JIT, CIM, and project
Facilities: Manufacturing managers need to understand the importance of
using existing facilities more efficiently. Responsibilities in this area
include facilities planning, equipment planning, production and inventory
control, and materials management.
Quality Management and Planning: Managers must
understand that quality cannot be mandated, and that it is an outcome of
outstanding management, systems, employees, and dedication. Also,
manufacturing quality efforts are part of the overall company-wide quality
policies, tools, and improvement efforts.
Scope of Manufacturing Management
Manufacturing management is a big job. It requires
integration, communication, and cooperation from all levels of a program,
from the systems program office (SPO), down through to the subcontractors.
Strong interaction with the customer facilitates the understanding of
manufacturing implications on cost and schedule.
Manufacturing management strongly emphasizes early involvement and
continuous improvement. Early on, its main objective is to identify and reduce
manufacturing risk. Manufacturing risk is the risk that the system will not be
manufactured to requirements within the cost, schedule, and performance
constraints of the program.
In determining manufacturing risk, such items as producibility,
manufacturing processes, tooling to be developed, testing and special test
equipment, and logistics must be considered.
The manufacturing management program continually assesses production
readiness. Production readiness is the degree to which a program is ready to
proceed into production. A program is ready for production when a producible
design is complete and the managerial and physical preparations necessary for
initiating and sustaining a practical manufacturing effort allow a production
commitment to be made without causing unacceptable risks of impact to
schedule, performance, cost, quality, reliability, maintainability, or other
Production readiness review (PRR) is a formal examination of a program to
determine if the design is ready for manufacturing, if manufacturing
engineering problems have been resolved, and if the contractor has adequately
planned for the production phase. The review may be conducted incrementally.
The Design Reviews reference guide discusses PRRs and associated reviews in
Manufacturing Management Example
MIL-STD-1528A, Manufacturing Management Program, provides an excellent
example of the type of structure that is required of a good manufacturing
management program.Table 8 (Acker, David D. and Young, Sammie G., LTC, USA,
Defense Manufacturing Management Guide for Program Managers, 3rd Ed., April
1989, Ft. Belvoir, VA: Defense Systems Management College, p. 10-2) summarizes
many of MIL-STD-1528A's requirements.
Table 8. MIL-STD-1528A Manufacturing Management
||Identify and Obtain Production
Identify and Resolve Risk
Identify and Obtain
Identify and Obtain Tooling and
Verify Manufacturing System
Program and Factory Planning
Integrate Industrial Material Management
Process and Methods
Design and Manufacturing Engineering
Production State-of-the-Art Analysis
Production Scheduling and Control
Control of Subcontractors and Vendors
|Contractor / Government Interface
||Manufacturing Management Program
Configuration Management and Change Control
Since the manufacturing plan is part of a hierarchy of documents that span
the life-cycle of a product, it is especially critical that it be maintained
and continuously updated. Manufacturing can be a major milestone in the
acquisition process, but it should never be an afterthought.
Inputs to manufacturing come from design, test, risk analyses, the SOW and
WBS, and logistics. Without a proper mechanism in place to ensure that design
changes are properly documented, manufacturing risk can never be mitigated.
Similarly, changes due to manufacturing decisions must be communicated if the
other organizations are to successfully deliver a producible design. The
Design Release and Configuration Control reference guides address the topics
of design release and configuration control in greater detail.
An input that is often overlooked in manufacturing planning is the
subcontractor. Subcontractors and vendors should be part of the development
team and are an integral part of the manufacturing process. A good working
relationship with vendors can lead to inventory reduction, reduced work-in-
process, reduced scrap and rework, increased floor space, reduced costs, and
an overall increase in quality.
Teamwork and communication with vendors regarding strategy, planning,
policy, and implementation issues can also facilitate the make-or-buy
analyses. The Parts Selection and Defect Control and Subcontractor Control
reference guides discuss many of the strategies and activities related to both
vendor and part selection.
A Sub-Contractor Quality Improvement Program
General Dynamics Corporation Electronics Piece Part Integrity - Product
Improvement Program is a part of an overall corporate quality initiative
intended to improve the overall quality of GD's products and increase the
productivity of their processes.
The policy is intended to improve piece part quality before fabrication and
assembly, thus building in quality. A common objective across all divisions of
the corporation is major improvement in throughput and end-item quality and
reliability. The program has five main features:
Establishing an electronic piece parts quality improvement program (QIP)
with selected suppliers. The primary objective of the GD/supplier QIP is
increased supplier product quality.
Performing component evaluation and reliability stress testing for
defectives. The objectives of this activity are to assure high quality
components for manufacturing and provide early feedback to suppliers. As
quality levels are achieved and maintained, the levels of testing may be
reduced or eliminated.
Implementing a closed loop feedback program. Timely feedback assures rapid
corrective action by suppliers and GD. Feedback also provides data to either
confirm a supplier's commitment to their quality goals or to identify areas
for corrective action.
Establishing a supplier performance evaluation and control program. The
main objectives of the source control program are to assure constant quality
and reduce testing such that random sampling can be done with little
Establishing a subcontractor flowdown plan. Also
referred to as the "Black Box Flowdown Plan," this program promotes the
involvement of subcontractors and the customers in a QIP to improve the
quality levels of "black boxes" that are assembled into GD's
Understand Manufacturing Issues
Attempts to plan what could be
referred to as the manufacturing process raise several issues and
sub-processes that are important to identify and define. In addition to
producibility, other factors that must be considered in the manufacturing
process include:(Nevins, James L. and Whitney, Daniel E., Concurrent Design of
Products and Processes, NY: McGraw-Hill, 1989, pp. 231-277.)
Part Fabrication and Assembly Process: Part fabrication refers to the
actual forming of parts into their desired shapes. The assembly process
details the sequence of steps required to put a product together.
Tolerances: Design tolerances affect each step in the manufacturing
process. Tightness of dimensioning and tolerancing requirements greatly
influences assembly sequence and product cost.
Feeding and Handling of Parts: Manufacturers needs to consider the
handling, transportation, and orientation of parts within the assembly
process. If a part is easy to grasp and orient for assembly, it is more likely
to be placed accurately.
Testing and Inspection: Testing and inspection can
help manufacturers to deliver high quality parts, as well as provide data
for statistical analyses. Complexities in assembly and fabrication increase
the likelihood of faults and defects. Testing of parts, subassemblies, and
final assemblies can identify commonly occurring faults and opportunities
for improved quality control and process improvement.
These issues, and many more, must all be considered and addressed during
the development of the manufacturing plan.
Contents of a Manufacturing Plan
A manufacturing plan is a compilation of a number of documents that detail
the system and factors necessary to achieve an effective, efficient
At different stages of a product life-cycle, the manufacturing plan
emphasizes different aspects of the manufacturing management task. Early on,
the plan attempts to describe a method to produce, test, and deliver a system
within time and cost constraints. The plan tries to detail how the method
would work, given the present set of facilities, tooling, and personnel
constraints. As the final Production Readiness Review (PRR) approaches, the
manufacturing plan becomes more detailed, describing the entire set of
manufacturing operations. Issues addressed in the plan include the
manufacturing organization, make-or- buy plans, resources and manufacturing
capability, and detailed production plans.
The actual contents of a manufacturing plan can vary greatly. The Data Item
Description (DID) for manufacturing plans (DI-MISC-80074), lists 27 different
types of information that may appear in a manufacturing plan. The Application
section of this guide discusses the manufacturing plan for the F-16 Fighting
Falcon, produced by General Dynamics.
The manufacturing plan also addresses a hierarchy of sub-plans it
addresses. Four of the major sub-plans that are tied to the manufacturing plan
Develop Tool Plan
There is often a great deal of confusion as to what the terms tooling,
special tooling, and special test equipment (STE) really mean. Many programs
refer to needing "tools and equipment" without a full understanding of what is
"Tool planning encompasses those activities associated with a detailed,
comprehensive plan for the design, development, implementation, and prove-in
of program tooling based upon a visible corporate policy and structured around
a documented practice. (NAVSO P-6071, p. 6-36.)
Tools can be thought of as the equipment (e.g., machines, machine tools,
instruments) required for producing a system. Examples of tools are drills,
lathes, milling machines, and robots. Generally, tools are considered those
items that can be acquired off-the-shelf and require little or no modification
for producing the system.
Special tooling is defined as:
"All jigs, dies, fixtures, molds, patterns, taps, gauges, other equipment
and manufacturing aids, and replacements thereof, which are of specialized
nature that, without substantial modification or alteration, their use is
limited to the development or production of particular services. (DSMC, p.
Basically, special tooling is the set of tools that must be developed for a
specific program or system. Special tools, by nature, are generally more
expensive than regular tools and require significant planning and design
efforts. An example of special tooling may be a custom end-effector for a
robotic assembly application. In this reference guide, "tooling" will refer to
Types of Tooling
Tools are generally thought of as either fixed or flexible (alternately,
"hard" or "soft"). Each type has an area of specialization and economic impact
that must be considered as early in the process as possible.
Fixed tooling is generally designed for a particular task, or a task where
there are few changes. Generally, fixed tooling is used for high-volume
production or pre-planned flexibility. Flexible tooling is reconfigurable for
a wide variety of tasks, and can be controlled and adapted by an operator or
sensors. (Nevins, James L. and Whitney, Daniel E.,Concurrent Design of
Products and Processes, NY: McGraw-Hill, 1989, pp. 285-289.)
Special Test Equipment
Special test equipment, also referred to as factory test equipment, are
those testing units that are essential to the testing and inspection of a
particular product during production, from unit assemblies up to the final
product. STE items do not include special tooling and general plant testing
items. STE can include custom-designed test fixtures and inspection
Types of Special Test Equipment
STE has two main functions: product inspection and test, and process
verification. As with tooling, these groups have areas of specialization and
economic impact that must be considered as early in the process as
Product inspection and test examines an item in manufacturing to evaluate
it visually and functionally for defects. STE can test for such things as
tolerances, manufacturing defects, fit and finish, and function to ensure that
the manufacturing process has not adversely effected the product. Process
verification examines how the process itself is performing. Measurement of
such things as tool wear, throughput, and yield help the company to determine
potential areas for improvement.
Testing of materials in process requires early consideration of testability
in all aspects of a product's design. The Design For Testing reference guide
addresses the issues of design for test and built-in test in greater detail.
STE also provides valuable data on product and process during manufacture.
Step 4 and the Parts Selection and Defect Control reference guide discuss the
importance of process monitoring and control as well as reinforcing the
notions of continuous improvement.
Production tooling and test equipment may require a significant investment
in time, money, and resources. Production of specialized equipment is a
development effort that requires the same type of up-front consideration and
planning as that of the entire system. Design, verification, and production of
tooling and test equipment must be concurrent and closely linked to the system
Custom tools and equipment can cost a great deal of money. Production rate,
material selection, number of different tools required, and design complexity
are the main cost drivers. Critical decision aids are trade studies, make-buy
analyses, producibility assessments, and risk assessments. These help to
identify problems early, when they are less likely to increase costs
The associated graph illustrates the tool/equipment selection process.
(Veilleux, Raymond F. and Petro, Louis W., Tool and Manufacturing Engineers
Handbook, Volume 5: Manufacturing Management, Dearborn, MI: SME, 1988, p.
19-7.) (press [F2] to see the associated graph)
Role of Tooling and STE
Traditionally, tooling was considered to be only the machines and machine
tools that were required for such jobs as metal cutting and forming. With
technologies ranging from composites to micro-electronics to computer vision,
the need for customized tooling and test equipment has increased.
By definition, tooling and STE are unique to a given process or product.
Concurrent engineering philosophy calls for an integrated design of product
and process. Tool planning and design must be part of any concurrent
Products and processes are driving the need for early definition of the
requirements of specialized equipment. Other parts of this guide address how
issues such as process planning, process qualification, and factory
improvements relate to manufacturing planning. Tool planning must be an
equivalent and integral function of the manufacturing effort as well.
Tooling and STE provide the means for creating and assuring the product
design and the process design.
A Tooling Lesson Learned
An example of the lesson learned from not being able to design or
understand the need for special tooling and test equipment can be found in the
A-12 Avenger program's cancellation. Defense Secretary Dick Cheney said that
the prime contractors were unable to "design, develop, fabricate, assemble,
and test the A-12 aircraft within the contract schedule."(NYT, January 6,
1991, p. 1.)
Problems with dealing with composites, a major item in stealth designs, was
the main reason the A-12 was 18 months behinds schedule and $2.7 billion over
budget. The prime contractors had limited experience with building large
composite structures, and literally had to develop the technology as the
program went along. Additionally the Navy's principle deputy general counsel
in reporting on the A-12, concluded that "the contractors underestimated the
level of effort needed to stabilize the aircraft design, as well as the impact
this would have on tooling and fabrication. In addition, they overestimated
their internal capacity for tool design and fabrication of metal-composite
components."(Braham, James, "What Price Stealth?", Machine Design, February
21, 1991, 63(4), p. 27.)
The Application section describes the tool planning strategy and activities
employed by Bell Helicopter for many of their designs.
Develop Manufacturing Process Qualification Plan
Methods such as design for assembly (DFA), design for manufacturability
(DFM), producibility engineering and planning (PEP), Taguchi methods, robust
design, and concurrent engineering stress the early integration of product and
process design. Yet, a highly manufacturable design is effectively worthless
if the manufacturing process to produce it is not available.
A manufacturing line is qualified if it can be characterized completely in
sources and amount of variation
conformance with standards (e.g., ISO 9000, ANSI,
DoD directives, MIL- STD's, tri-service regulations)
Qualifying the manufacturing process improves
manufacturing performance by ensuring:
By successfully focusing on a process involving both design and
manufacturing engineers, a company is ensured of producing products in volume,
on time, and within cost. Design engineers should consult with manufacturing
engineers to further refine the process using production equipment. The
successful blending of engineering and manufacturing can be facilitated by
expert systems, engineering work stations, and integrated databases.
Production sample is one means of qualifying the manufacturing process. It
enables a company to obtain information about the manufacturability of an
item, using actual production equipment and processes. The feedback from
building the production sample can be used to improve the design and
manufacturing processes. It also enables a manufacturable product at a lower
cost and higher quality.
Training is an important ingredient in implementing the qualified
manufacturing process. Design and manufacturing engineers determine the
training needed in the production environment. Designers should follow the
product out to the production floor and perform many of the training
Important steps in process qualification are: process characterization and
process capability studies. (Keyser, Jack. "Manufacturing Process Control," in
Microelectronic Reliability, ed. Edward B. Hakim, Norwood, MA:Artech House,
1989, pp. 215, 219-221.)
Process characterization involves:
identifying the steps in the process
listing variables present in each step
listing the normal values for variables that have
control over the process
A process can be characterized using process flow charts, cause and effect
diagrams, and determining current process parameter settings.
Flow charts document the steps in the process, identify the inputs to the
process and outputs of the process. Cause and effect diagrams determine the
parameters acting on each step of the flow chart and factors that may or may
not affect the output.
Process Capability Studies
Process capability concerns the process variation and the variables
affecting quality and productivity of the process.
Process capability studies determine:
whether the process can meet objectives, such as design specifications,
customer needs, etc.
the inherent or natural variation (behavior) of a
process, identify and eliminate causes underlying any unnatural
The factors internal to the manufacturing process are: materials,
processing machinery and test equipment, the process itself, time-related,
operators, and automatic controls embedded in the process.
The external sources of variation are those external to the manufacturing
process itself. They may come from within the company or from an external
customer. They are powerful driving forces and may have a significant impact
on the product quality. Some of the most significant external forces are cost,
management, schedules, and environment.
In addition, process qualification enables the following:
Process optimization - conducting studies and experiments to determine
preferred levels of process parameters
Process and product control and monitoring - establishing the new level of
performance, obtaining control, regular monitoring to maintain control
Process improvement - adopting continuous
improvement as a practice
A Process Qualification Program
Upon recognition of the fact that its competitive environment was
characterized by powerful competitors, sophisticated designs, rapidly changing
technology, and increasing customer expectations, the Westinghouse Electronic
Systems Group (ESG) examined its focus on the product/process
ESG created Producibility Assurance Centers (PACs) and Transition Assurance
Centers (TACs). The PAC/TAC idea is to foster the integration of the design
and manufacturing processes. The basic theme of the PACs is to emphasize
flexibility, creativity, and innovation in product and process design. The
TACs serve to represent the initial pilot production lines to validate the
manufacturing processes prior to starting full-rate production.
In ESG's Advanced Interconnect Technology Laboratory, the PAC/TAC strategy
achieved a 50% reduction in the time to move to next generation of printed
wiring packaging technology from development to production. (Teixeira, John,
"Concurrent Engineering," paper presented at the 4th Annual Best Manufacturing
Practices Workshop, September 11, 1990, Scottsdale AZ.)
Sample Manufacturing Process Qualification Checklist
Table 9 presents a general checklist used qualify manufacturing processes
according to a set of certification requirements. The checklist is often
tailored to specific processes as needed. (Personal communications with C. J.
Keyser, AT&T Bell Laboratories)
Table 9. Manufacturing Process Qualification Checklist
| MANUFACTURING PROCESS QUALIFICATION |
| Certification Requirements |
| | A | M | I |
| Manufacturing flowchart with identified inspection | | | |
| checkpoints, input and output variables (parameters) | | | |
| Experienced/trained operators, certified where necessary | | | |
| or desirable | | | |
| Experienced/trained maintenance personnel | | | |
| Appropriate supervision | | | |
| Knowledgeable about process and product requirements | | | |
| Certified inspectors | | | |
| Adequacy of facilities | | | |
| Facilities (equipment) maintenance program | | | |
| Calibration system | | | |
| Assembly instructions, work instructions, or standards | | | |
| Inspection procedures | | | |
| Latest issues of drawings and specifications available | | | |
| Incoming material and parts - inspection and control | | | |
| Traceability, serialization, or lot identification | | | |
| Control of non-conforming product | | | |
| Inspection results recorded, maintained, and used for | | | |
| process improvement | | | |
| General housekeeping | | | |
| Overall compliance with quality plan | | | |
| A = Adequate M = Marginal I = Inadequate |
Qualified Manufacturers List Program
To reduce the cost of electronic components, semiconductor manufacturers
and the government are participating in a joint effort to qualify the
manufacturing processes for monolithic microcircuits (under MIL-I-38535) and
for hybrids (under MIL-H-38534/MIL-STD-1772).
The qualified manufacturers list (QML) effort takes advantage of the
near-zero defect levels many semiconductor suppliers achieve. The QML program
recognizes that incoming inspections are costly and are not needed when
suppliers implement SPC programs to ensure quality is built in. The objective
of QML is a 10-fold to a 100-fold decrease in the price of silicon
microcircuits. (Burgess, Lisa. "Thomas: Pushing the Pentagon Toward QML."
Military and Aerospace Electronics, February, 1990, pp. 39-40.)
With QML, the manufacturing processes are certified rather than individual
parts, as in current Qualified Parts List (QPL) and MIL-M-38510, General
Specification for Microcircuits. The traditional approach of certifying parts
under the Joint Army Navy (JAN) programs and under the MIL-M-38510 program was
costly, lengthy, and inefficient. (Gardner, Fred. "Hold Down Ballooning Costs
and Boost Quality." Electronic Purchasing, June 1988, p.57.) Parts became
obsolete almost as soon as they were qualified. The lengthy audit process had
to be repeated with each upgrade. QML eliminates the need to re-qualify parts
from a certified line.
The key element of QML is in-process monitoring of the manufacturing
processes to ensure device yield and reliability.
The benefits of the QML program are:
better control of manufacturing process
better use of facilities
fewer government audits and lower qualification costs
predictable part costs
improved delivery schedules
A product should not be released to the production floor until there is
sufficient proof that the product is manufacturable. The desired end result of
a qualified process is predictability by repeatability. In general, developing
a manufacturing process qualification plan is a good business practice because
it ensures cost-effective programs and operations.
The Application section discusses the case study of AT&T
Microelectronics' manufacturing facility in Allentown, PA, which was the first
facility to have its manufacturing processes qualified.
Develop Factory Improvements Plan
Factory improvement does not just mean updating the equipment in the
factory. It involves striving to achieve an integrated and supportive mix of
layout, material flow, inventory control, manufacturing processes,
maintenance, and plant control. An organization must be able to assess the
value-added of the technology before investing capital.
...a productive factory is not a collection of isolated machines or
automated systems; it is a single, integrated effort. (Fife, William J. Jr.,
"The Automation Imperative," Assembly, 1990 Buyer's Guide Issue, July 1990, p.
Factory of the Future
The factory of the future has traditionally been viewed as a high-tech,
automated "lights out" operation with few or no human operators. This
misconception has led to many companies investing a great deal of capital in
order to automate processes they do not understand. As far back as the 1950s,
organizations sought to put in new systems based on new, unproven technology
without fully understanding the scope of their efforts. (Havatny, Josef,
"Dreams, Nightmares, and Reality," Computers in Industry, 4(2), 1983, pp.
High-tech does not necessarily mean replacing human operators with robots.
It means re-thinking processes and determining the best mix of people, tools,
machines, and resources. It means combining this understanding with product
design in order to determine the most efficient and cost-effective
manufacturing processes. (Royce, WIlliam S.,Is Manufacturing Obsolete?,
Business Intelligence Program, Report No. 83-800, Menlo Park, CA: SRI
International, 1983, pp. 10-15.)
The concept of CIM is covered in greater detail in the Computer-Assisted
Technology reference guide. The basic idea in developing a CIM architecture is
that a quick fix will not necessarily provide lasting improvements. CIM
requires an organization to address several key issues:(Harmon, Roy L. and
Peterson, Larry D., Reinventing the Factory, NY: Free Press, 1990, pp.
Product Engineering: It is critical to understand and define the links
between design engineering and its tools (e.g., CAD, CAE, GT).
Process Engineering: To properly generate plans and instructions,
manufacturing engineers need to work out the interactions between CAM, CAPP,
and factory equipment.
Manufacturing Planning and Control: Planning and execution of master
production schedules require a proper understanding of such concepts as MRP II
Factory Support: Resources must be available to support scheduling,
tooling, and maintenance.
Factory Execution: Coordination and control of machines, operators, and
cells facilitate the production of quality products.
Automation: Identify areas where automation is needed, such as high- volume
repetitive functions and material storage and retrieval systems.
Information: Connectivity and integration require
clear channels of communication between people, machines, and
Automating a problem still leaves a problem. Companies must understand the
processes, simplify them, automate where needed, and then integrate the
Decisions regarding manufacturing equipment must be made with consideration
of the equipment's reliability. Manufacturing can not be competitive if the
production line continually has problems. There is a strong need to rediscover
Traditionally, maintenance was focused on preventive and corrective
practices. While practical and valuable, preventive maintenance is not enough
when things like time to market and JIT are considerations. Manufacturers need
to account and plan for predictive and diagnostic maintenance also. Planning
for the maintenance tasks is discussed in the Develop Operations Plan
Maintenance responsibility does not just belong to the manufacturing
organization. Suppliers also should take an active role in designing and
proving their equipment prior to installation in a factory. Accordingly,
manufacturers should include the suppliers as part of their factory
improvement planning team.
Material Handling, Flow, and Inventory
Initiatives and techniques such as that JIT, FMS, cellular manufacturing,
automated material storage/retrieval systems, CAPP, and GT strive to provide
solutions which address concerns of material inventory, supply, handling, and
Automation of the production can have many payoffs; automation of the waste
before and after the production makes little sense. (Shonberger, Richard J.,
World Class Manufacturing, NY: Free Press, 1986, p. 45.)
The key point to remember about material handling is that it must
efficiently support the manufacturing process. Material must be able to move
through the manufacturing facility so that the entire environment works
smoothly. Material handling can help to reduce inventory, control inventory,
and free space on the factory floor. If material is not handled well process
efficiency suffers. Damaged parts, for example, increase the amounts of scrap
and rework. (Bergstrom, Robin P., "Some Things Just Don't Translate Well,"
Production, 102(12), December 1990, pp. 54-57.)
The physical layout of a factory directly influences the efficiency of the
production system. In a JIT system, for example, the facility is designed to
minimize work-in-process, material handling, and cycle time, while improving
feedback. The manufacturing process, equipment considerations, and material
handling concerns must all be included in the layout planning function.
(Lubben, Richard T., Just-In-Time Manufacturing,NY: McGraw-Hill, 1988, pp.
Whether undertaking a re-layout of an existing facility or looking for
opportunities to improve the present facility. The company has to understand
how the layout currently functions. To get a firm grasp on how the layout
affects processes, has to consider physical and economical constraints as well
as practical limitations. Areas of analysis include product volume and mix,
production processes, production departments and tasks, material flow, and
space requirements. Additionally, layout decisions must offer benefits to both
the company and the employees, not just the manufacturing bottom line. (Usher,
John S. and others, "Redesigning An Existing Layout Presents a Major Challenge
- And Produces Dramatic Results," Industrial Engineering, June 1990, 22(6),
Building control has been included in the past 20 years in the integration
considerations of manufacturing facilities. Heating, ventilation, air-
conditioning, waste management, and safety systems often have a direct
influence on the production processes. For example, in electronics
manufacturing, temperature, humidity, and airborne particles have direct
impact on the process yields. Integrating these plant operations with
manufacturing operations can help reduce wastes, control downtime, and
diagnose problems. (Benassi, Frank, "Honeywell Integrates Building and Process
Controls in Factories," Managing Automation, March 1991, 6(3), pp.
JIT: A Misunderstood Philosophy
The Japanese success in implementing the just-in-time (JIT) manufacturing
control philosophy has led many American firms to view it as a "must do" to be
successful in manufacturing. Many companies have implemented, JIT without
fully understanding what it really means. JIT's basic philosophy is
simplification through waste elimination. Waste is anything that does not add
value to the process or product. JIT attempts to identify all non-value-added
activities and remove them. JIT is not:(Veilleux, Raymond F. and Petro,
W. Tool and Manufacturing Engineers Handbook, Volume 5: Manufacturing
Management, Dearborn, MI: SME, 1988, p. 2-18.)
an inventory program
an effort that involves suppliers only
a cultural phenomenon
a materials project
a program that displaces MRP
a panacea for poor management
JIT and MRPII
Manufacturing resource planning (MRPII) and its predecessor, materials
requirements planning (MRP), deal with material scheduling, inventory
management, capacity planning, and shop floor control (both are discussed in
relation to CAM and CIM in the Computer-Assisted Technology reference guide).
There is a misconception that JIT and MRPII systems cannot work together. In
fact, a properly designed MRPII system supports JIT by facilitating planning
and identifying requirements prior to implementation. (Goodrich, Thomas, "JIT
& MRP CAN Work Together," Automation, April 1989, 36(4), pp. 46-48.) (The
Determinant Factors for a Successful MRPII Implementation, Saratoga Springs,
NY: Business Education Associates, 1987.)
For example, it is not "JIT" when JIT parts delivery is achieved by having
a vendor set up a warehouse in the parking lot.
The associated graph illustrates the activities in a comprehensive JIT
manufacturing system. (Veilleux, Raymond F. and Petro, Louis W. Tool and
Manufacturing Engineers Handbook, Volume 5: Manufacturing Management,
Dearborn, MI: SME, 1988, p. 2-19.) (press [F2] to see the associated
Develop Operations Plan
The operations plan helps companies to manage shop floor processes. The
plan helps fill the gap between industrial engineering and production. Often
referred to as shop floor control or plant floor management, the operations
plan connects the actual execution of functions with the data required for
successful manufacture and measurement.
"In a totally predictable production environment, demand forecasts would
always be realized; bills of materials would be absolutely accurate; suppliers
would ship their orders on time and with total accuracy; nothing would be
misplaced or miscounted in the storeroom; machines on the shop floor would
never fail; all manufacturing personnel would be present when expected; and
all intervals in the process would be fully predictable. (Doshi, Bharat T. and
Krupka, Dan C., "Integration of Planning and Execution Operations: Theory and
Concepts," AT&T Technical Journal, July/August 1990, 69(4), p.
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A process plan is the detailed description of how raw
material is transformed into a finished part. Process planning is the method
used to describe a part (e.g., dimensions, tolerances, materials), identify the
manufacturing steps, and map the product design with the production process.
(Bhaskaran, Kumar, "Process Plan Selection," International Journal of
Production Research, 1990, 28(8), pp. 1527-1539.) The associated graph
(Adapted from Sutton, George P., Computer-Assisted Process Planning, Business
Intelligence Program, Report No. 765, Menlo Park, CA: SRI International, 1988,
p. 2.) illustrates the function of process planning. The Computer-Assisted
Technology reference guide defines, discusses, and gives examples of process
planning and computer-aided process planning (CAPP). (press [F2] to see the
The process plans provide the basic instructions for manufacturing a
product. The plans are very detailed, exactly specifying such things as how to
set up and operate a machine, work instructions, time standards, bills of
materials, engineering drawings, inspection, part classifications, parameters
(e.g., feed and speed of cut), cost estimates, and reference documents.
(Gould, Lawrence., "Putting a CAPP on CIM," Managing Automation, August 1990,
5(8), pp. 17-19.) (Metz, Sandy, "Making Manufacturing Better, Not Just
Faster," Managing Automation, August 1990, 5(8), pp. 22-24.)
The process plans provide cost and time estimates to the shop floor. Once
the process is up and running, these estimates can be compared to the actual
values, thus evaluating the estimates and processes and identifying potential
areas for improvement.
The DoD refers work instructions through MIL-HDBK-50A, which stated "all
work affecting quality shall be described in clear and documented instructions
of a type appropriate to the circumstances."(MIL-HDBK-50A, Evaluation of a
Contractor's Quality Program, June 26, 1990, p. 11.) Documenting instructions
for areas such as assembly, fabrication, processing, inspection, and test
helps ensure that production occurs in the fashion prescribed by the process
planning. As with requirements, it is critical that the instructions be clear,
timely, and concise. Additionally, they must provide qualitative and
quantitative criteria when appropriate.
Operators generally perform tasks from sets of step-by-step instructions,
illustrations, and references to other documents. Often, each instruction is
independently generated (either manually or by computer) and maintained so
that it is difficult, if not impossible, to retrieve a complete document at
any given time. Because of this, it is vital that the information be managed
effectively throughout the process.
To assure quality, work instructions must be well coordinated and
communicated throughout the facility. It is critical that the instructions on
the floor match the design of the product currently in production. The wrong
set of instructions during manufacturing could severely affect product
quality, reliability, and overall cost. A complete configuration management
system allows coordination not only during development, but also in
Paper or Paperless?
A fully integrated work instruction system should include:(Report of Survey
Conducted at Lockheed Missile Systems Division, Sunnyvale California, Best
Manufacturing Practices Program, OASN-PI(RD&A), August 1989, p.
documentation that is readily available at the operators station
illustrations integrated with instructions
control and accountability
synchronized distribution of documentation
support for traceability and audit of the
Traditional systems are paper-driven. There is a push towards paperless
operations using central repositories for data and operator workstations. The
Application section presents a case study where Northrop converted the F/A-18
assembly line to a paperless operation.
Maintenance is the ability to plan, manage, and control while maximizing
the uptime of a facility's production processes. Maintenance provides
manufacturers with the means of keeping their facilities in top-notch
Successful and profitable companies include maintenance as a critical
component of an effective manufacturing program. Operations plans must also
account for maintenance of plant equipment. Good maintenance involves more
than just fixing broken equipment. It also involves diagnosis and monitoring
before a problem occurs. The "Don't fix it until it breaks" attitude has
proven to be very costly(Benassi, Frank. "Maintenance Management:
Manufacturing's Final Frontier." Managing Automation. March 1991, p.
The benefits from a proper maintenance program include increased uptime and
output; reduced scrap and rework; reductions in unexpected production costs;
improved product quality and consistency; control of product and production
costs; the ability to meet JIT manufacturing commitments and delivery
schedule; reduced unexpected capital expenditures for equipment; and the
extended life of capital equipment.