CONSTRUCTION-RELATED APPLICATIONS OF BARCODE TECHNOLOGY

Introduction

"A small picket fence of narrow and wide bars. A beam of orange light. An electronic beep.

A number on a digital display. The technology comes at you with a disarming simplicity." [1]

With the exception of those individuals directly involved in the food industry or certain aspects of the retail trade, the majority of Americans are relatively oblivious of Barcode Technology. Unfortunately, most construction personnel fall into this same category.

The capability of rapid, accurate, data entry and manipulation by use of barcodes offers substantial advantages for a broad spectrum of the construction industry. Typically, data entry by barcode takes two seconds or less per item and actual Department of Defense testing demonstrated one "read error" per 3,379,458 entries even when using labels printed by dot matrix printers. Using commercially printed labels, the "read error" rate is quoted at one per 70,000,000. This is in stark contrast to entry error rates on the order of one per 300 for manual data entry.[2] An additional benefit of the mechanized data entry method is the reduced level of intimidation for those with "computer phobia."

Alternate media such as Optical Character Recog­nition (OCR), Magnetically Incoded Character Recognition (MICR), and Magnetic Stripes have significant disadvantages in the construction environment.

OCR, which has had relatively wide utilization in the clothing industry, is significantly more difficult to read via a hand scanner. The reader may recall watching as a clerk made several attempts to scan an OCR label only to resort in desperation to keying in the data. In addition, the "read error" rates for OCR are on the order of one in 10,000 even in relatively clean environments.[3]

MICR, which is the standard for the banking industry, suffers from similar environmental limitations.Magnetic stripes are common on credit and bank cards and have the advantages of being able to encode a relatively large amount of data in a limited space as well as being readily recoded. Their disadvantages as construction adaptable media include sensitivity to dirt and magnetic fields.[4]

Historic Milestones

Wallace Flint, a 1932 Masters Degree Candidate at the Harvard Business School, suggested in his Thesis the automation of grocery store checkout stands by having the customers present punched cards to the cashier for subsequent machine reading and calculation of their bill. The idea was offered unsuccessfully to several grocery retailers. [5]

In 1949 a patent for a circular barcode was filed by N.J. Woodland, et al and a pilot barcode checkout system was installed by Kroger in Cincinnati, Ohio in 1967.[2]

Realizing that a standardized industry-wide coding system was a prerequisite to effective implementation, the National Association of Food Chains (NAFC) commissioned Logicon, Inc. to develop such a code.[5] In 1973, the Univer­sal Produce Code (UPC) was adopted with the first operational system being installed at Marsh's Supermarket in Troy, Ohio the following year. [2]

In 1975 Code 39 (also known as Code 3 of 9) was developed and subsequently adopted as the official Department of Defense symbology in 1981 and immediately some 50,000 suppliers found themselves suddenly plunged into the barcode business. Since DOD was requiring that all incoming containers have the Code 39 labels, each of the 50,000 suppliers was forced to find a source of labels or to acquire label printing equipment.[6]

Having also been adopted by the Distribution Symbology Study Group (DSSG), the Automotive Industry Action Group (AIAG), the International Air Transport Association (IAIA), the Aluminum Industry, the Health Care Industry, and the French Pharmaceutical Industry, Code 39 has emerged as the dominant barcoding system among the more than 60 codes that have been developed.[2]

SYMBOLOGY

Commonly encountered barcode symbologies include the UPC, 2 of 5, Interleaved 2 of 5, Codeabar, and Code 39. Typically, these codes require "quiet zones" or unprinted areas at each end of the code, encode the data by use of multiple bar widths, and have built in self checking systems to reduce errors.

The UPC Code, which is the standard for the Food Industry and widely utilized in the retail trade, is a 12 character code consisting of a guard bar, a number system code, 5 characters indicating the manufacturer, a center bar pattern, 5 characters indicating the specific product, a check character, and guard bar. UPC requires exacting printing tolerances and encodes numbers only. [5]

Code 2 of 5 is constructed with 5 bars per character, 2 of which are wide with the remaining 3 narrow. Primary utilization has been for inventory purposes, airline ticketing and baggage handling, and photofinishing processing. In this system only the bar width is a part of the code and the width of the spaces has no significance. Due to this characteristic, Code 2 of 5 labels tend to be relatively long and are also limited to numbers only.[7]

The interleaved 2 of 5 has been used in the automotive industry and for marking corrugated

containers. In this adaption of Code 2 of 5, the spaces are a part of the code resulting in a more compact code, but the code is still limited to numerals only.[2]

The Codeabar symbology utilizes a complex pattern of 18 bar widths that has been utilized by libraries for automated checkout procedure, by blood banks for identification of individual blood containers, and by Federal Express for parcel identification. This code makes provision for numerals as well as a limited number of symbols. [2]

The Code 39 symbology consists of sets of nine bars in two widths such that 3 wide bars and 6 narrow bars are used to encode each character. This configuration, where 3 of the 9 bars are wide, and the fact that the code initially contained 39 characters gave rise to the name. Currently, the code has 43 characters including a start/stop character, 10 numeral characters, 26 letter characters, and 6 symbols. This symbology provides a relatively dense (short) code that has the highest level of data security of all available codes. This combination of attributes makes Code 39 the best choice for adoption by the construction industry. [8]

COMPONENTS

In spite of their broad capabilities, barcode systems require relatively small investments of time, hardware, or software for implementation.

Obviously, a source of barcoded labels is required in the proper format for the code selected. A wide spectrum of label sizes, materials, adhesives, and protective coatings is available commercially and inexpensive software programs are likewise available to permit on-site printing of the labels by use of a dot matrix, ink jet, or laser printer.

A great deal of information is available on the relative merits and costs of the various alternatives.[2,3,4,6,8,9,10,11,12,13] This information may be summed up as follows: "In a bar code system.... the code image may be generated by any acceptable means on any accept­able medium where acceptable means only that the code can be read by the intended reading device. "[13]

Once the code is printed and attached to the object, a scanner is required in order to "read" the code. The scanners applicable to the construc­tion industry include the "light pen" or "wand" and a hand held laser scanner.

The light pen, which is similar in size and shape to a fountain pen, consists of a light source and light receptor in the same housing. The pen may utilize a fiber optic bundle, a jeweled tip, a lens assembly, or an apertured emitter/sensor to achieve the "read" function, but in all cases the operation is identical. The operator places the tip in contact with the label in the "quiet zone" and manually scans across the code to the following "quiet zone."

The operator will have to develop a technique of scanning the barcode depending upon the type of pen and the reflectivity of the label. Typically, a learning time on the order of 10 minutes is required for proficient scanning. [2] Since the light pen has no moving parts, they can be produced to be virtually maintenance free. One manufacturer claims their light pen can be run over by a forklift without being damaged.[6] Since the operation of the light pen requires contact with the label for reading, it is obvious that dirty environments and inacces­sible labels would preclude or hinder the use of this device.

The hand held laser scanner can "read" the barcode from a distance of 6 to 8 inches. [6] This permits operations under conditions that would be prohibitive for the light pen. In addition, the laser scanner casts a visible band of light that the operator can guide to the label to be scanned. Thus the learning curve for the laser scanner is even shorter than that of the light pen.

Since the reader decodes the characters directly from the label in ASCII format, the scanner output is immediately usable by the computer. The signal can be channeled to the computer through an emulation device or directly to a communications port. When the signal is routed through a emulation device, known as a "wedge," the data is handled by the computer is exactly the same manner as if the data were entered through the keyboard. Alternately, the scanner can be directly coupled to the RS232 communications port on a personal compu­ter.[8]

Some applications such as inventories, material takeoff, and the like can be most expeditiously handled by use of a portable data terminal (PDT). The portable data terminal functions as a hand held computer with a capacity on the order of 64K which receives, stores, and down loads the data to the main computer.[14]

Software has been developed specifically for barcode applications, but most construction related functions can be handled by use of conventional commercial software programs. In developing a pilot demonstration program for CII, the various data bases were set up by use of dBASE III plus and required a commun­ications program to interface the data input with the main program. The software program "Crosstalk" was selected and used for this function. [14]

CASE HISTORIES

Ford Motor Company assembles heavy trucks in a 67 acre building with 9.5 miles of conveyors. Since each of these vehicles is built to customer order, the manufacturer must draw from an inven­tory of 24,000 different parts and assemblies and have the correct components arrive at the right place and time along the conveyor. All material receiving, warehousing, automated picking, and conveying are controlled by barcodes.[15]

A major motor freight carrier found that "lost" shipments, even though they amounted to less than 1% of the total of items handled, were prohibitively expensive. When they replaced their manual means of control with a barcoded system, they eliminated more than 99% of the "lost" items and recovered the cost of imple­menting the system in the first 7 months.[6]

Belknap Hardware was operating a 9 story, 1,800,000 square foot warehouse in Louisville, Kentucky at maximum capacity using their manually operated data recording system. The implementation of a barcoded material management system for their 65,000 items, permits orders from their 300 salespersons to be entered with the orders picked and shipped the same day.[11]

Federal Express ships and monitors approximately 450,000 parcels per day by a barcoded system. A unique barcoded label is manually keyed in at the receiving station and the system is automated thereafter. At each station the label is scanned and the parcel is routed to its destination and the location and time is updated in the computer file. This permits the carrier to determine the location of any parcel within its system within 15 minutes and to accurately forecast the delivery time.[6]

Since the Department of Defense has implemented a barcode material management system, they have documented 20% savings in inventory costs, 30% reduction in receiving processing time, and 9.5% reduction in shipping time. The total projected annual savings due to the barcode system is $113.9 million.[16]

The retail grocery industry estimates that barcoding produces a cost savings of 1.5% of the gross sales volume.[3]

An aerospace firm improved inventory accuracy by 20% within 6 months of the time that the barcode controlled system was implemented which resulted in a $2.2 million savings in carrying costs along with a $1 million savings from reductions in materials in inventory.[17]

CONSTRUCTION APPLICATIONS

Material Inventory

Statement

During the course of construction at the typical jobsite, materials are received from a variety of vendors and occasionally from the owner as well. All of the materials must be accounted for and most of them must be stored for some period of time. Damaged goods or shortages must be acknowledged and claims filed. Vendors invoices require reconciliation with purchase order quantities, prices, material receipts, and payment made in accordance with the agreement and/or to receive applicable discounts. Materials built into the work as well as materials on hand must be incorporated into the monthly billing to the owner, and materials placed into or removed from the contractor's inventory must be accounted for. In a major construction project thousands of items from hundreds of vendors stored in numerous warehouses or laydown yards must be tracked. The potential for waste, duplication, or misman­agement is very real.

Proposal

Even though the majority of material suppliers are not currently equipped to provide barcode labels on their products, the implementa­tion of a barcode material inventory system is relatively simply and inexpensively adopted. The contractor must select the symbology and ensure that the appropriate incoded information is placed on the incoming materials via a label that can be reliably "read" under jobsite condi­tions. This will require in most cases that the contractor provide the labels to the material supplier and require that they be attached to the materials prior to receipt at the jobsite. This provision can be written into the terms of the purchase order as a condition of payment.

Upon receipt of the material at the jobsite, a hand held laser scanner and portable data terminal could be used to "read" the barcoded labels on large items for subsequent transfer to the computer. Smaller items could be handled by use of a light pen or laser scanner directly connected to the computer. In either case, the file created when the purchase order was issued would be accessed and information such as quantity, assigned storage area, and the like would be immediately available. In addition, the material would be "logged in" by date and time alone with any comments as to damages or shortages. Materials leaving the warehouse or laydown yard would then be scanned along with the employee badge of the individual obtain­ing them. If several projects are being served from a single warehouse or laydown yard, the issuance of a "project card" which would also be scanned would link the material with the project and employee and simultaneously adjusting the inventory for the warehouse or laydown yard. A report showing materials removed from storage for the period would be used for monthly billing purposes.

Application

One major engineering contractor has implemented a system similar to that described above on 3 construction projects. In addition to the control over material status and location, the contractor has reported a 50% decrease in manpower requirements for inventory operations. [8]

Tool and Equipment Checkout

Statement

A contractor may have a number of tools and items of equipment such as backless, dozers, trucks, welding machines, cranes, pumps, compressors, and the like that are available for use at one of several jobsites. Often the particular item may be needed at more than one location at a time and a decision must be made relative to its allocation. In addition, items may not be in a state of readiness for service due to lack of maintenance or repair, may have been lost or stolen, or may located at a particular jobsite where they are not needed.

Ideally, the location and condition of each tool and piece of equipment would be known at all times, the proper repairs and maintenance would be done, and the project to which the individual item is assigned would be charged for the use of each item.

Proposal

The attachment of barcoded labels to each tool or item of equipment along with the issuance of barcoded employee badges and "project cards" will permit the implementation of the automated checkout procedure. The employee requesting a specific item would present his/her employee badge along with the "project card". These would be scanned along with the label on the item to create a file identifying the item, the employee, the project, and the time and date of the checkout. This would provide an audit trail for the item as well as provide a basis of charging the project for operation/ amortization costs.

When the tool or item of equipment is checked in, the label is scanned which updates the file to indicate that the item has been returned and charges the operation/amortization costs to the project. An on-screen prompt will request that the condition of the item be described as "serviceable", "requires repair/maintenance", or "scrap". Reports will list each of the three categories to indicate items ready for checkout, items requiring service prior to returning to ready for checkout status, and those items that should be disposed of and removed from the depreciation schedules.

Application

A west coast shipyard was operating with 3,000 employees on three shifts. A total of more than 3,000,000 tools and pieces of equipment was available for checkout at 22 separate locations. The manual checkout system was slow and inefficient causing long lines of employees waiting for items, low morale, hoarding of scarce items, "lost" tools, duplicate issues, and tools issued to subcontractors without proper billing ever being done.

The barcode issue system adopted provides a centralized computer with a satellite unit at each point of tool issue where the scanning of the tool label along with the employee badge to creates a file. If the issuance to that employee will produce a duplicate issue, the issue is denied until the employee turns in the previously issued tool. If the tool is issued to a subcontractor, a similar file is created to produce the record for billing pur­poses. Since the life of various brands of tool can also be monitored, the most cost effec­tive brands of tool can be purchased for replace­ment.

The system is so efficient that the entire $1.2 million cost was recovered in less than 9 months.[6]

Safety Equipment Issue

Statement

The issue of safety equipment to employees of most construction firms is generally not closely monitored. Since the unit cost of safety glasses, hard hats, and the like are relatively low, the cost of an adequate manual cost control system may not seem justified. Due to the lack of proper controls, employee misuse of the system is common. An employee who forgets safety glasses or wants a duplicate pair for use at home could easily say his/her glasses were broken and request an additional issue. In addition, the lack of inventory control results in shortages of some items and excess quantities of others without giving the opportunity for optimum purchase procedure.

Proposal

when an employee requests the issuance of an item of safety equipment his/her badge and the item will be scanned. If the employee is listed in the data base as being currently employed, the safety equipment requested is compatible with the employee's classification, and no previous issue of that equipment has been made to that employee, the issue is author­ized. If a previous issue has been made, the employee will be requested to turn in the unser­viceable item before issue of the replacement is authorized. If the unserviceable item is not turned in and the employee still requests the reissue, the employee is charged for the item via a payroll deduction. On-screen prompts will require an input as to whether the charge is to be made to the employee or the company.

Application

A large contractor implemented a system as described using a portable barcode reader to replace a manual checkout system. Even though significant time savings were real­ized in the data entry, the primary advantage in the system that employees are reluctant to attempt to abuse a system that uses a computer to monitor their activities. On a major construc­tion project, the contractor reported issue of equipment was reduced by 1/3 as compared to the former system. [8]

Estimating

Statement

Significant advances in estimating procedures have been made in recent years. The advent of computer aided systems and fully computerized estimating systems has provided increased accuracy and reduced manpower require­ments as compared with manual methods. Even with the latest in hardware and software systems, a method of entering the data is required. Alternatives include keying in the data, use of a digitizer, as well as utilization of bar-coded tablets.

Proposal

Major construction projects are often estimated by a team of estimators each of which has an area of expertise. By concentra­ting upon a particular area, the estimator develops techniques and procedures that simplify and expedite the quantity takeoff operation. If an estimator then encodes the various commands that he/she regularly uses in barcode format along with barcodes for the digits 0 through 9 and the decimal point, a custom tablet can be easily developed for the estimator.

Application

A large engineering contractor has developed a system similar to that described above. Using this system, estimators with custom tablets and light pens enter the data into portable data terminals. Since the computer is not tied up by this operation, several estimators, each with a PDT, light pen, and tablet can work on one or more estimates at a time. Since each PDT can store up to 64K of data, significant amounts of the estimate can be completed before the data must be down loaded to the main computer. The system is reported to provide increased accuracy along with a 30% reduction in estimating time.[18]

Drawing Tracking

Statement

On large, complicated construction projects maintaining a complete, up to date set of all drawings as well as tracking the drawings from individual to individual and from company to company while indicating the current status and location of each drawing is a time consuming task.

Proposal

A unique barcode can be printed on or attached to each drawing. When the drawing is issued to an individual or company, the drawing code as well as the code for the individual or company is scanned creating a file record. As activities such as revisions, approvals, and the like are completed, the appropriate codes from a tablet along with the drawing code are scanned to update the file. In this way, the status and location of each drawing can be tracked and the length of time that the drawing has been at any location can be determined.

Application

On a nuclear power plant with 750,000 engineering drawings an average of 800 drawings per day were checked in or out of the central file. Implementation of a barcode document tracking system reduced the data entry time from 2 hours per day to just 7 minutes per day.

CONCLUSION

The advantages offered by barcode technology are such that the medium sized or large con­struction firm can ill afford to ignore them. The lack of an industry-wide standard for bar­coding means only that the contracting firm is required to develop "closed" systems that only operate within their own firm rather than utilize "open" systems such as used within the food industry.

If the firm develops and implements their own "closed" systems using Code 39 symbology, it is likely that if industry-wide "open" systems are developed, adaptation to the new system can be fairly easily achieved.

REFERENCES