Forest Service

Northeastern Forest Experiment Station

Research Paper NE-666

Graphic Model of the Processes Involved in the Production of Casegood Furniture

Kristen G. Hoff Subhash C. Sarin R. Bruce Anderson

guidelines for process timea

work oenter~chedub C

uppiies if in feedback loop

BOM C

Abstract

Imports from foreign furniture manufacturers are on the rise and American manufacturers must take advantage of recent technological advances to regain their lost market share. To facilitate implementation of technologies for improving productivity and quality, a graphic model of the wood furniture production process has been developed using the IDEF (!CAM- Integrated Computer Aided Manufacturing-minition) modeling process and is presented. IDEF modeling provides a graphic representation of the production process by presenting the information in easy-to-grasp chunks. A description of the modeling process explains how the model represents the data that flows through the plant, the activities in the plant, and their interaction. Analysis of the model may result in improved communication, recognition of specific points for implementing new technologies, evidence of bottlenecks and problem areas, simplified inventory control, or reduction of paperwork.

The Authors

KRISTEN G. HOFF is a research industrial engineer wlth the Northeastern Forest Experiment Station's Forestry Sciences Laboratory at Princeton, West Virginia. She received a B.S. in mathematics and computer science from Concord College, Athens, West Virginia, in 1985 and an M.S. in industrial and systems engineering at Virginia Polytechnic Institute and State University, Blacksburg, Virginia, in 1991. She joined the Northeastern Station in 1987.

SUBHASH C. SARlN is a Professor in the Department of Industrial and Systems Engineering at Virginia Polytechnic Institute and State University, Blacksburg, Virginia. He received a Ph.D. in operations research and industrial engineering from North Carolina State University, Raleigh, North Carolina. Previously, he held a faculty position at Ohio State University, Columbus, Ohio. He worked with IBM during the summer of 1983 as advisor to the Manufacturing Systems andAobotics Development Department.

R. BRUCE ANDERSON is an economist with the Northeastern Forest Experiment Station's Forest Sciences Labratory at Princeton, West Virginia. He received a B.S. degree in forest science from The Pennsylvania State University, University Park, Pennsylvania, in 1965 and an M.S. degree in wood science from the same institution in 1970. He received a Ph.D. in forest economics from Virginia Polytechnic lnstitute and State University, Blacksburg, Virginia, in 1988. He currently is working with the Northeastern Station's Advanced Hardwood Processing and Technical Resource Center at Princeton.

I

Manuscript received for publication 14 May 1992

Northeastern Forest Experiment Station 5 Radnor Corporate Center 100 Matsonford Road, Suite 200 P.O. Box 6775 Radnor, Pennsylvania 19087-4585

August 1992

Introduction

Pls imports from foreign manufacturers increase, American wood furniture producers are searching for reasons for this loss of market share. Foreign competition in the furniture industry has increased significantly since 1972, and the greatest competition has been in the wood furniture category (U.S. Department of Commerce 1985). To regain market share, U.S. wood furniture manufacturers need to use new technologies. To better communicate and analyze manufacturing for applying the new technologies and irnproving productivity, a graphic model of the wood furniture production process has been developed. The model represents the functions of the wood furniture production system and the information and objects that interrelate with those functions.

Reasons for Loss of Market Share

The Myth of Labor Costs

The most common perception among American manufac- turers for the cause of this increased competition is reduced labor costs associated with many foreign countries, especially those in the Pacific Rim. While this may have been true in the past, it is no longer true today. For example, Taiwan, for many years, has enjoyed the advantage of lower wage rates than the U.S. However, today Taiwanese firms faced with labor shortages operate below capacity. The factory workers that are available are demanding higher wages and improved working conditions (Smith and West 1991). Since this trend occurs as coun- tries become more industrialized, it is reasonable to expect wage rates to climb in other Pacific Rim countries, also.

European manufacturers have no advantage in labor costs since wages in European countries are nearly the same as, or higher than, American wages. Aggregate figures for the 16 European countries for which 1988 data is available (Fig. 1) show that in 1986 European countries paid an average hourly rate at 83 percent of the United States average, 101 percent in 1987, and 105 percent in 1988 (I1.S. Department of Commerce 1989).

The Reality of Quality

One reason for the U.S. loss of market share is the resistance of American manufacturers to design products with customer expectations in mind. In a recent international quality study conducted by the American Quality Foundation and Ernst & Young, it was discovered that Japanese companies are three times as likely as American and Canadian businesses to incorporate customer expectations into the design of new products and services. Furthermore, German businesses are twice as likely as North American businesses to translate customer expectations into the design of new products and services (Bemowski 1991).

1 I2O [ . USA LZ Europe -77

(USA= 1 00) YEAR

Figure 1. -Index of American and European hourly compensation costs (USA=100).

Clearly, to improve the perceived quality of American products by meeting customer expectations is key to increasing the market share. New technologies must be applied to respond to customer expectations in a timely fashion, and employees need training in the application and implementation of the technologies. Models of manufacturing systems ensure that all employees not only understand the current system, from raw materials to finished product, but can effectively determine potential points for implementing new technologies.

Strategy for Improvement

By educating the workforce on the complete manufacturing process and the tools and techniques used to evaluate productivity and quality, America can regain its competitive status. The 1988 ASQCIGallup survey reported that employee education is one of the most important ways to improve quality in American business (Ryan 1989). A practice common to recent winners of the Malcolm Baldridge National Quality Award is the implementation of training courses in managing for quality, making improve- ments, and using the tools and techniques available (Juran 1991). Before improvements in quality can be realized, managers must recognize the points where quality problems are likely to arise, where improvements are needed, and at which new techniques may be applied effectively.

Once expertise on managing for quality is acquired, new tools and techniques must be applied to gain control of the manufacturing process. "Gaining total control of the process requires a system applied uniformly across the operation, from raw materials to finished product, so that communication barriers come down via a common language and common format." (Slater 1991). A graphic model can be used to explain the manufacturing process to individuals not familiar with the furniture industry, as well as to pinpoint areas where quality might be a problem before final assembly.

Description of Model

This paper presents the graphic model of a typical casegood furniture plant. The model (Appendix A) was developed using the IDEF (!CAM- lntegrated Computer Aided ~anufacturin~- niti ion)^ modeling process developed by the U.S. Air Force program for Integrated Computer Aided Manufacturing ([CAM) (Softech, Inc. 1981). The basic premise behind the process is that the human mind has the ability to accommodate any amount of complexity if it is presented in easy-to-grasp chunks that fit together to make the whole. To impose the restriction that only related information is shown on any single chart, the IDEF method limits a function to six or fewer subfunctions; thus a consistent level of detail for each function within a chart is maintained and decision points become apparent.

In using the IDEF method, each box in the model represents a function. Figure 2 contains six boxes, each representing a major stage in the production of wood furniture. Each arrow entering a box from the left represents an input and each arrow exiting a box from the right represents an output of the function. As shown in Figure 2, the order preparation stage (prepare order box) produces the supplies (including lumber, hardware, fasteners, adhesives), due date, and work center schedule. However, to see all the intermittent steps, it is necessary to explode the box into several smaller boxes. This decomposition is shown in Figure 3. Each of these boxes, prepare cutting order and procure supplies, in turn, can be decomposed further, hence Figures 4 and 5.

Arrows entering from the top represent constraints. For example, in Figure 2, the moisture content of the lumber is considered a constraint since moisture will affect how long it will take to prepare the lumber for processing. Arrows entering from the bottom represent mechanisms or devices needed to execute the function which that box represents. In Figure 6, the stickers placed in between the lumber to facilitate air flow are considered devices.

In addition, the IDEF method associates a node index with the entire set of charts. The node index, an outline of the process, is generated by assigning a number to each box within a single chart. If a box is exploded into another chart, each box within this chart is numbered and that number is appended to that of the "parent" box. The process continues recursively until entirely catalogued. The node index provides a listing of all the functions and is formatted to show "parent" functions and their "offspring." For example, Figure 2 is the overview of the process and is assigned the number 1 A. Prepare order, a decomposition of the first function, is designated 1Al; prepare lumber, 1A2; dimension pieces, 1A3, and so on. Figure 3 generates 1 A1 I, prepare cutting order, and 1 A1 2, procure supplies.

I ~ h e use of trade, firm, or corporation names in this publication is for the information and convenience of the reader. Such use does not constitute an official endorse- ment or approval by the US. Department of Agriculture or the Forest Service of any product or service to the exclusion of others that may be suitable.

If no greater level of detail is required for a particular function, then it is not imperative to generate additional boxes even though other functions that follow may require further decomposition. The complete node index for the entire process is presented immediately following the model in Appendix B.

The model describes the manufacturing processes of a dresser, bureau, or nightstand. It may be customized easily to show specific production lines for additional parts such as doors, or different procedures such as a gang-rip- first cutup operation.

Previous Applications

The IDEF modeling process improves problem analysis, requirements definition, and functional specifications through the rigorous expression of complex ideas that had seemed too abstract and obscure to treat technically. The'process does not solve problems; it is a tool that allows people to express, understand, manipulate, and check problem areas.

The U.S. Air Force provides the showpiece of this te"cnology in their CAM program. Thousands.of people from hundreds of organizations working on more than one hundred major projects used the methodology not only for the technical work of system definition and design, but for project management and integration as well.

Additional applications of this tool include system design, package design, documentation organization, curriculum design for teaching, and project estimation and management. Some specific examples are separation of function and design in environment control systems; uncovering overlooked tasks in the structure of a software development project; and assessment of the impact of factory modernization on engineering, purchasing, quality assurance, and shipping. Furthermore, one large corporation applied the IDEF product specification and design diagrams to meeting control; participants addressed specific issues and made decisions with less effort and time than before using IDEF (Ross 1985). These examples demonstrate the breadth of problems addressed using the IDEF modeling procedure.

Future Applications

Within the wood furniture industry, the possible benefits of applying the IDEF modeling process are vast. As furniture manufacturers move to respond to customers more quickly and take advantage of new technologies, they must analyze their product and current production system to determine which technologies are applicable and feasible. The analysis must also uncover points where the new technologies may be integrated with the current system. By modeling the production process with IDEF, such an analysis would be greatly facilitated.

Inventory control may be improved by diagram analysis to pinpoint areas where excess inventory is generated.

SCHEDULE "I SCHEDULES

MOISTURE COMPLETED MARKED OFF

M/C' SPEEDS FOR PART

LUMBER -DRIED TYPEOF

BOARDS LUMBER

DIMENSION PIECES

PIECES

M/C* SPEEDS FOR LUMBER

f SHAPE

ASSEMBLE (

PACK

* Machine.

~igure 2.- 1 A Overview.

inventory I" hd

I revision of work center schedule)

work center schedule b

order

Figure 3.-Decomposition of prepare order.

bill of materials m due date

~ w r k center schedule d

PREPME ORDER

(for possible

PROCURE SUpPLlES

supplies rC

due date

receipt date of supplies )

guidelines for process times

DETERMINE WHERE ESTABUSH due date

receipt of PLACED supplies if in feedback loop Il

IAll

Figure 4.-Decomposition of prepare cutting order.

on hand inventory

bill of materials DEDUCTONHAND FROM BOM AND

UPDATE ON HAND I workcenter s c h e d u l ~ I , I (

vendor's productbn whedule and on hand inventory

need-to-buy l i t supplies 1 P g E k i doaired delivery data WNEN gE DOR on-tlmedeliverydat{

work center schedule delayed deliiry dates C

I due date b

work center schedule +

lA12

Figure 5. -Decomposition of procure supplies.

Similarly, production flow may be streamlined as bottlenecks become obvious. Diagramming of the entire production system reveals work-in-process accumulation. Once such problems are identified, steps can be taken to resolve the congestion, such as adding another machine or rerouting work to a different machine.

Paperwork may be reduced and information flow improved. When all inputs to a function are identified, they may be checked, one by one, to see if that information is necessary to the function. If it is not necessary, that transaction can be eliminated and the information provided only when it is necessary. Conversely, by analyzing the IDEF model, it may become apparent that information required for a particular function may not be carried through formal communication channels. In this instance, a direct line of communication may be opened, thus eliminating the need for a production employee or expeditor to trace the information.

Decision making should improve. The IDEF model allows

Literature Cited

Bemowski, Karen. 1991. The international quality study. Quality Progress. 24(11): 33-37.

Juran, J.M. 1991. Strategies for world-class quality. Quality Progress. 24(3): 81-85.

Ross, Douglas T. 1985. Applications and extensions of SADT. Computer. (4): 25-34.

Ryan, John. 1989. Is U.S. quality competitiveness back? Quality Progress. 22(12): 37-39.

Slater, Roger H. 1991. lntegrated process management: a quality model. Quality Progress. 24(3): 91-94.

Smith, Paul; West, Cynthia. 1991. The Taiwan and Korean furniture industries. Import/Export Wood Purchasing

managers to analyze a specific subsystem while considering its interrelations with the system as a whole. Previously overlooked factors that influence decision making are revealed. In addition, downstream factors may have more bearing on decisions than previously realized, forcing decisions to be made too soon.

Setup time may be reduced once production employees become familiar with the entire manufacturing system. Also, when design engineers are acquainted with the complete process, design for manufacture can be implemented. An additional operation early in the production process may eliminate two or more operations later on. In addition, the change may be accomplished more easily earlier in the process. The IDEF model shows the most frequent changeover occurrences and which changeovers constrain the system.

The IDEF model of the wood furniture production process may be analyzed to shed light on a wide range of problems, not just those listed here. Only after these problems are defined, can they be addressed.

News. 17(4): 3, 24, 26, 28.

Softech, Inc. 1981. lntegrated computer-aided manufacturing (ICAM) architecture, Part II, Vol. IV - Function modeling manual (IDEF-0) AFWAL-TR-81- 4023. Vol. 4. Waltham, MA. Air Force Wright Aeronautical Laboratories, Wright-Patterson Air Force Base, OH. 167 p.

U.S. Department of Commerce, Bureau of Labor Statistics. 1989. Statistical abstract of the United States 1990. Report 771. Washington, D.C. Table 1465, p. 849.

U.S. Department of Commerce, International Trade Administration. 1985. A competitive assessment of the U.S. wood and upholstered furniture industry. Washington, D.C. 50 p.

Appendix A - IDEF Model

dried lumber

1 A2

work center sct

-

-

type of lumber used for this

REVISED WORK -+ CENTER SCHEDULE

desired moisture content

completely dried boards

CONTENT

order (from production control)

uideline information on ROW long to dry lumber

not dry enough J boards

rk center schedule +

stacks --LU dried boards

WORK CENTER * SCHEDULE WITH DELAYS SHOWN I

green lumber

-7

UNSTACK

STACK BOARDS of boards -

OF ONE KIND t DRY due date

OF LUMBER BOAROS work center schedule

lumber (boards)

+stickers due date

Figure 6.-Decomposition of prepare lumber.

- t WORK CENTER

p ~ ~ p m ~ SUPPLIES

ORDER DUE DATE

WORK CENTER -

SCHEDULE SPEEDS PREPARE FOR PART

TYPE OF

BOARDS LUMBER

SCHEDULES , WIACTUAL

WORK COMPLETED MARKED OFF

DIMENSION PIECES LUMBER

PIECES f

SHAPE

4 ASSEMBLE I

* Machine.

Figure 7. - 1 A Overview.

order 1 bill of materials

on hand inventory

PROCURE SUPPLIES

Y

supplies - due date

5- receipt date of supplies

------I (for possible '

revision of work center schedule)

work center schedule

Figure 8. - 1 A1 Prepare order.

DETERMINE WHERE ON SCHEDULE

ORDER IS TO BE PLACED

supplies if in feedback loop

due date ___)

DETERMINE BILL OF MATERIALS

(BOM)

guidelines for process times

due date 1 ESTABLISH ---------) WORKCENTER BOM - -1 SCHEDULE

due date + work center schedule

e

BOM e

Figure 9.- 1 A1 1 Prepare cutting order.

I on hand inventory

bill of materials DEDUCT ON HAND FROM BOM AND

UPDATE ON HAND h work center schedule INVENTORY

RECORDS

need-tebuy list CUT

due date

work center schedule

PURCHASE I

vendor's production schedule and on hand inventory

I delayed delivery date.

purchase order . PlACE ORDER

desired deliverv date W/VENDOR

due date P

supplies rn

on-time delivery dates

1 work center schedule w

i Figure 10. - 1 A1 2 Procure supplies.

dried lumber

desired moisture content

type of lumber used for this order (from production control)

FI uideline information on ow long to dry lumber

stacks dried boards green lumber STACKBOARDS boards

OF ONE KIND I = 'ILN DRY due date BOARDS -

work center schedule

due date work center schedule

REVISED WORK ---+ CENTER SCHEDULE

not dry enough i I- WORK CENTER SCHEDULE WITH I

boards 1 DEIAYSSHOWN

, .................................

i PREPARE 1 j CUlTING i

i ORDER I .................................

UNSTACK BOARDS

lumber A (boards)

Figure 1 1. - 1 A2 Prepare lumber.

type of lumber desired

GET STACK(S) OF BOARDS OF

TYPE OF LUMBER SPECIFIED ON

work center WORK CENTER SCHEDULE

desired moisture content

type of lumber

guideline information on how long to dry lumber

1

Figure 12. - 1 A22 Kiln dry boards.

work center ADJUST CONTROLS work center schedule

b

dried boards U I

work center schedule BOARDG 3 I saw speed

current required lengths from , , , I ] { {cutting bill

supplies - I

pieces cut to length SEPARATE ~ ~ ~ S S C U T due date BOARDS

BY Iwork center schedulA LENGTH t 1

groups of pieces with same length

due date 4

supplies

rough pieces of size

due date PIECES

work center schedule

saw speed

supplies f I I core pieces

L

work center schedule b

-

Figure 13. - 1 A3 Dimension pieces.

RIP BOARDS

pieces of a propriate length cut o width due date

! @

, work center schedule

GLUE BOARDS

TOGETHER

current required lengths from cutting bill

P 1

planed boards dried boards b DETERMINE WHERE dried boards

due date SCAN BOARD - due date CROSSCUTS SHOULD

due date b FOR DEFECT work center schedule GO TO GET LARGEST

t human eye or vision system

PLACE IN WASTEBINS

t operator or vision system's computer algorithm

saw speeds for type of lumber

due date

____t

I crosscut saw

*work center schedule with actual work completed marked off.

Figure 14. - 1 A32 Crosscut boards.

cutting bill requirements

pieces supplies cut to lendh

work center C,

schedule

SET SAW BLADES FOR DESIRED

WIDTHS

pieces

saw speed for part type lumber

pieces cut to width - D-

FEED BOARDS , due date L 7

THROUGH RIP SAW work center schedule*

D-

1 waste pieces and sawdust

PLACE IN WASTE BINS

* work center schedule with actual work done marked off.

Figure 15.-1 A33 Rip boards.

work center schedule workcenter schedule work center schedule

SELECT PIECES SUCH glue pieces THAT THE TOTAL WIDTH

APPLY COMES CLOSEST TO GLUE due date DESIRED WIDTH WITHOUT I GOING UNDER work center schedule work center schedule

glue roller ball

rough pieces of size

PUT ANDCURE TOGETHER k: work center schedule

glue wheel or hig h-frequency elecbonic bonding machine

=igure 16.- 1 A35 Glue boards together.

I required thickness of piece

rough pieces of size RESURFACE TRIM PIECES TO

due date UNIFORM LENGTH

work center schedule

core pieces APPLY VENEER OR

work center schedule *

VINYL COATING b-

Figure 17. - 1 A36 Trim pieces.

UT O W BASIC

SHAPES

completed shaped pieces shaped pieces

I

SHAPE due date EDGES

/ supplies I I due date 1 1

work center work center schedule schedule I 1 1 1

sanded pieces B-

supplies =- INSPECT

1 accessible pieces RTA**

I work center schedule*

duedate PIECES inaccessible after assemb

work center flawed pieces P

repaired pieces

REWORK FLAWED PIECES

ly pieces

-7

STAIN PIECES WHICH W I U BE VISIBLE ONLY PART OF THE

stained

pieces RTA

*work center schedule with actual work done marked off.

** Ready to Assemble.

Figure 18.- 1 A4 Shape pieces. -

! tenacity of lumber

core pieces shaped pieces

supplies I

supplies

due date

. . due date

EXTERIOR SHAPE*

due date

work center schedule 3 work center schedule

sawdust

- . . . -. - I work center schedule I u

machines* t

* machines for this operation would ~nclude routers, lathes, tenoners, planers, and shapers.

( tenacity of lumber I

shaped and carved basic pieces c ** profiling mlc's, drills, carving mlc's, and boring mlc's.

CARVE INTERIOR flawed pieces 4-----

sawdust

1 PLACE

IN WASTE

!machines** 1 BINS

Figure 19. -1 A41 Cut out basic shams

supplies -A due date SETUP MACHINES

saw speeds for type of lumber

sha ed ieces R ~ R ~ : ~ ~ completed pieces su lies

due date M/C's TO I flawed pieces

SHAPE EDGES I sawdust 1 A

machines*

A

PLACE IN WASTE BINS

* machines may include moulders, dovetailers, mitering machines.

Figure 20. - 1 A42 Shape edges.

required thickness of piece

7 completely mostly sanded pieces supplies

b SET UP c- RUN PIECES

supplies due date .

SANDING due date THROUGH due date center scheduleb MACHINES wok center scheduE SANDERS work center schedule

sawdust ,__________________I_______________________I_______________________I_______________________I_______________________I_______________________ I

1 REWORK \ rework 1 j FLAWED I

1 1 TOUCHUP I w INTRICATE

C WORK BY

SANDING BY

I HAND

sanded pieces c PLACE IN

WASTE BINS

Figure 2 1 . - 1 A43 Sand pieces.

schedule --T

sanded pieces -------- flawed pieces

human operator

supplies c

due date work center

L

ready-to-assemble (RTA) pieces

marking pencil

schedule-

SCAN SURFACES

supplies MARK

due date c FLAWS

work center

Figure 22. - 1 A44 Inspect pieces.

RTA which do not require b-

pre-assembly staining RTA which require pre-assembly COUNT RTA

NUMBER PASSED

~NSPECTION

staining

count of number passed *

(work center schedule with actual work done marked off)

flawed pieces (minor) . FILL IN filled pieces FWWS

(major)

PLACE IN WASTE

paint brush

SMOOTH OUT

FILLING

I iron

repaired pieces

Figure 23.- 1 A45 Rework flawed pieces.

pieces I supplies ASSEMBLE frames due date FRAME I---- accuracy

of saw operator

1 + PUT R M v E S barewood furniture

supplies b

AND DRAWERS

, TOGETHER

work center schedule c-

pieces supplies

ASSEMBLE due date DRAWERS work center schedule L l

I texture of wood

count of finished goods (work center schedule with work done marked off) * finished goods *

I I Iokaved bare furniture 1 1 INSPECT -1 gz r] AlTACH + supplies supplies

HARDWARE

Figure 24. - 1 A5 Assemble parts.

outside frame c accuracy I accuracy of saw of saw

operator' supplies due date 7 work center schedule * pieces

_I RUNNERS 1 frame _I PA&T ( frame , supplies

ATTACH

screws 7-

AnACH SIDES

TOTOP

A r n H

Figure 25. - 1 A51 Assemble frame.

4

Astap~es ' staples

supplies

Ushape

or dowel pins

AlTACH SHELVES

or screws

I accuracy of 1 accuracy of

work center schedule TOBACK 1 / BOllOM 1

saw operator saw operator

pieces

bracket, 1 cjrtaiIingl t staples

supplies supplies U shape ATTACH

supplies b

due date h

A

1 accuracy of

-

JOIN SIDES .

saw operator supplies drawer box

DRAWER FRONTS

drawers C

Figure 26.- 1 A52 Assemble drawers.

accuracy of saw operator

frames INSERT Ucasen r - l

supplies

drawers *-

DRAWERS INTO

FRAMES

I screws

AFFIX supplies STOPS

Figure 27. - 1 A53 Put frames and drawers together.

barewood furniture w

VISUALLY y furniture -1 SCAN 1 flawed barewood furniture PIECES t

Figure 28. - 1 A54 Inspect.

SPECIAL

texture of wood

Supplies +/ FILL AND / treated I / stained furniture

furniture 7 I L -

texture of wood

SEAL AND STAl N

supplies b

PERFORM HIGH

GLOSS RUBDOWN

stained furniture (glossy)

- - - - -

Figure 29.-1A55 Stain and finish.

I texture of wood

I

supplies A RUBOFF

supplies 7 + w ~ ~ w

treated furniture

stained furniture (1 st coat)

Figure 30. - 1 A552 Fill and stain.

ON BAREWOOD stained furniture RUNS stained furniture -

dull, stained furniture FURNITURE

texture of wood

v

Figure 31 .- lA553 Seal and stain.

RUBOFF

P

supplies

stained furniture

supplies

stained furniture - APPLY FINISH

type of furniture

1 hardware kit ASSIGN

s " ~ ~ ' i e s 4 'IT 1- KIT TO 1 I HARDWARE - PIECE furniture TO PIECE .

I furniture I I w/kit - 1

supplies ATTACH HARDWARE

furniture

t supplies _I WIPE OFF

supplies I count of finished goods INSPECT 1 4 FURNITURE

finished furniture _ 1 1 finished goods 4

Figure 32. - 1 A56 Attach hardware.

THOROUGHLY furniture VISUALLY

INSPECT PIECE

okayed furniture INCREMENT

+ COUNT OF 1 flawed furniture FINISHED

1 GOODS BY 1

count of finished aoods

finished goods *

PLACE IN BUFFER

Figure 33.-1 A565 Inspect furniture.

due date tr-7 work center schedule

finished good +I 2x4 I piece mostly

I crowbar

supplies

wrapped piece

tape

FIT BOX ~ ~ O U N D

supplies '

piece loosely

boxed

TRUCK of furniture

SEAL TOP OF

BOX

supplies _____C

boxed piece

Figure 34. - 1 A6 Pack and ship.

TRANSPORT TO WAREHOUSE

OR WAITING

Appendix B - Node Index

1A. Overview 1 A1 . Prepare order

1 A1 1. Prepare cutting order 1 A l l l . Determine where on master schedule

order is to be placed 1 A1 12. Determine bill of materials 1 A1 13. Establish workcenter schedules

1 A1 2. Procure supplies 1 A1 21. Deduct on hand inventory from bill of .

materials and update on hand inventory records

1A122. Cut purchase orders 1 A1 23. Place order with vendor

1A2. Prepare lumber 1A21. Stack boards of one kind of lumber 1A22. Kiln dry boards

1A221. Get stack(s) of boards of type of lumber specified on work center schedule

1A222. Move and put in kiln and adjust controls 1 A23. Test moisture content 1 A24. Unstack boards

1 A3. Dimension pieces 1 A3l. Plane boards 1 A32. Crosscut boards

1A321. Scan board for defect information 1A322. Determine where crosscuts should go to

get largest clear area of desired length 1 A323. Crosscut boards 1A324. Place in waste bins

1A33. Separate boards by length 1A34. Rip boards

1A341. Set saw blades for desired widths 1A342. Feed boards through rip saw 1A343. Place in waste bins

1A35. Glue boards together 1 A35l. Load selector 1A352. Scan pieces 1A353. Select pieces such that the total width

when glued together comes closest to desired width without being under desired width

1A354. Apply glue 1A355. Put boards together and cure

1A36. Trim pieces 1 A36l. Resurface pieces 1A362. Trim pieces to uniform length 1A363. Apply veneer or vinyl coating

1 A4. Shape pieces 1A41. Cut out basic shapes

1A411. Set up machines 1A412. Cut exterior shape 1 A4l3. Cawe interior designs 1 A41 4. Place (flawed pieces and sawdust) in

waste bins 1A42. Shape edges

lA42 l . Set up machines 1A422. Run pieces through machines to shape

edges 1 A423. Place flawed pieces and sawdust in waste

bins 1A43. Sand pieces

lA43l . Set up sanding machines 1A432. Run pieces through sanders 1A433, Touch up intricate work by sanding by

hand 1A434. Place sawdust in waste bins

1 A44. Inspect pieces 1 A441 . Scan surf aces 1A442. Mark flaws 1A443. Place in scrap lumber pile 1A444. Count number passed inspection

1A45. Rework flawed pieces 1 A45l. Fill in flaws 1A452. Smooth out filling

1A46. Stain pieces which will be visible only part of the time

1A5. Assemble parts 1 A51. Assemble frame

1 A51 1. Attach sides to top 1 A51 2. Attach shelves 1 A513. Attach runners lA514. Attach to pallet

1 A52. Assemble drawers 1 A521. Join sides to back 1A522. Attach bottom 1A523. Attach drawer fronts 1A524. Attach slides (and blocks)

1A53. Put frames and drawers together 1A531. Insert drawers into frames 1A532. Affix stops

1 A54. lnspect 1 A54l. Visually scan pieces 1 A542. Mark flaws 1A543. Pull off assembly line 1A544. Put in buffer area

1A55. Stain and finish 1A551. Treat with special effects (highlight, fly

speck) 1A552. Fill and stain

1A5521. Spray stain on bare wood 1A5522. Rub off runs 1A5523. Dry furniture

1A553. Seal and stain (top coat) 1 A553l. Apply finish (glaze) 1A5532. Rub off runs 1A5533. Dry furniture

1A554. High gloss rubdown 1 A56. Attach hardware

1A561. Kit hardware 1A562. Assign kit to piece 1A563. Attach hardware to piece 1A564. Wipe off furniture 1 ~ 5 6 5 . lnspect furniture

1A5651. Thoroughly inspect piece visually 1A5652. Increment count of finished goods

by one 1 A5653. Mark flaws lA5654. Pull off line 1A5655. Place in buffer area

1A6. Pack and ship 1A61. Wrap in packing material

1A62. Fit box around piece 1A63. Seal top of box 1 A64. Remove furniture from pallet 1 A65. Seal bottom of box 1A66. Transport to warehouse or waiting truck

Sr U.S. GOVERNMENT PRINTING OFFICE: 1992--648-139/40,026

Hoff, Kristen G.; Sarin, Subhash C.; Anderson, R. Bruce. 1992. Graphic model of the processes involved in the production of casegood furniture. Res. Pap. NE-666. Radnor, PA: US. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. 39 p.

Imports from foreign furniture manufacturers are on ,the rise, and American manufacturers must take advantage of recent technological advances to regain their lost market share. To facilitate the implementation of these technologies for improving productivity and quality, a graphic model of the wood furniture production process is presented using the IDEF modeling process. Description explains the data that flows and the activities that occur in the plant, and their interaction. By analyzing the model, communication may be improved, specific points for implementing new technologies may occur, bottlenecks and problem areas may become evident, inventory control may be simplified, and paperwork may be reduced.

Keywords: Wood furniture production; quality improvement; productivity improvement; IDEF

Headquarters of the Northeastern Forest Experiment Station is in Radnor, Penn- sylvania. Field laboratories are maintained at:

Amherst, Massachusetts, in cooperation with the University of Massachusetts

Buriington, Vermont, in cooperation with the University of Vermont

Delaware, Ohio

Durham, New Hampshire, in cooperation with the University of New Hampshire

Hamden, Connecticut, in cooperation with Yale University

Morgantown, West Virginia, i n cooperation with West Virginia University

Orono, Maine, in cooperation with the University of Maine

Parsons, West Virginia

Princeton, West Virginia

Syracuse, New York, in cooperation with the State University of New York, College of Environmental Sciences and Forestry at Syracuse University

University Park, Pennsylvania, in cooperation with The Pennsylvania State Uni- versity

Warren, Pennsylvania

Persons of any race, color, national origin, sex, age, religion, or with any handicap- ping condition are welcome to use and enjoy all facilities, programs, and services of the USOA. Discrimination in any form is strictly against agency policy, and should be reported to the Secretary of Agriculture, Washington, DC 20250.

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