COA8903-IT Adoption in the Building Industry (Reinforcement)

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COA8903-IT Adoption in the Building Industry (Reinforcement)

Chang-sun Chin

1. Objectives

The purpose of study is to diagnose the existing processes and business environment, to find available and suitable information technologies, to make a framework target plan, including assessment of potential benefits, to assess the expected costs of achieving the plan, and to analyze the readiness of the reinforcement industry sector for implementation framework plan.

1. Introduction: Existing processes and business environment
2. Architects and engineers produce their drawings using computer generated design format (AutoCAD…) or paper format
3. The reinf. bar fabricators receive drawings in these formats and reproduce them on paper for reinf. bar fabrication (Bar bending Schedule)
4. To date, process of reinf. bar fabrication (cutting & bending) has been automated in part.
5. Needs to utilize and manipulate this information more efficiently and effectively: enhance the integrated process from engineering/design to fabrication / assembling.
6. Existing Processes

2.6.Existing business environment

2.6.1.“Concrete Industry comprises establishments primarily engaged in the use of concrete and asphalt to produce parking areas, building foundations, structures, and retaining walls, and in the use of all materials to produce patios, private driveways, and private walks. Activities performed by these establishments include grout and shotcrete work. The concrete work performed includes new work, additions, alterations, and maintenance and repairs.”[1]

2.6.2.Concrete contractor (in the U.S.)[2]

Number of Establishment / 30,417 nos.
Value of Construction work / $ 25,848,848,000
New construction / $18,737,938,000
Additions, alterations, or reconstruction / $3,558,605,000
Maintenance & repair / $3,217,936,000

2.6.3. U.S. Apparent Consumption of Rebar[3]

1. Available information technologies

3.1.Improving the flow of information between all parties involved in the rebar design, supply and construction chain

3.2.RebarCAD System & CADS RC(Bar bending Schedule)

3.3.aSa suite of rebar applications

3.4.CAD-Integrated Rebar Placement Planning (CRPP system (increasing the productivity of rebar design, detailing, fabrication, delivery, and placement)

3.5.Bamtec* system (Alternative reinforcement)

3.6.RebarCAD System-Key Benefits[4]

.

3.7.

3.6.1Productivity

3.6.2Accuracy - virtually eliminates errors and reduces inconsistencies in detailing and scheduling (take-off).

3.6.3Flexibility - detail any arrangement of bars in any type of structure and is not a restrictive modular system that can only detail standard units such as footings, etc.

3.6.4Efficiency - Links with fabrication management / production systems reduces data re-entry to provide a total solution.

3.7. CADS RC-Key Benefits[5]

3.7.1. Fast Accurate Detailing

3.7.2. Automatic Bar Lists / Schedules

3.7.3. Automatic Detailing Macros

3.7.4. Links to RC Design Software

3.7.5. Links to Fabrication Systems

3.7.6. Powerful Editing Systems

3.7.7. Reduced Checking/Errors

3.8. aSa-Key Benefits[6]

3.8.1. Quickly and accurately develop an estimate, leading to a successful bid

3.8.2. Record customer, job, and delivery information for contract or walk-in orders

3.8.3. Rapidly enter material and produce a variety of office, shop, and field reports

3.8.4. Shear, bend, and move steel in the shop, while reducing scrap and pacing the operation

3.8.5. Track material from pre-fabrication, to cutting, bending, trailer loading, and installation

3.8.6. Accurately track inventories of stock and remnant material

3.9. CAD-Integrated Rebar Placement Planning System[7]

3.9.1. The impact of automating control of the entire rebar fabrication operation on safety and productivity should also be investigated

3.9.2. A human-machine control interface should be analyzed for its effect on the fabrication operation as well as the product quality.

3.9.3. The model proposed for full integration of adaptive control in the rebar fabrication environment may also be modifiable for application to other construction material fabrication or prefabrication operations.

3.10. Alternative Reinforcement Technology[8] (* Bamtec)

3.10.1. Concrete slab reinforcement which is rolled out on site just like a carpet.

3.10.2. Rolls can be delivered to site in lengths up to 15m wide and 30m long.

3.10.3. Bamtec can be used instead of both standard mesh and cut and bent bar.

Benefits for Contractors /

Benefits for Consulting Engineers

1.Savings in fixing costs of up to 90%.
2.Material savings of between 20-40%.
3.Fast-track construction.
4.Increased quality management.
5.Reinforcement fixing in computer controlled factory environment.
6.Just in Time supply. / 1.Shorter and more automated design time.
2.Shorter and more automated detailing time.
3.Reduced opportunity for human error.
4.Consultants drawings are reproduced exactly on site, not to a steel fixer's interpretation of the drawings.
5.Reduced requirement for resident engineering.

1. The potential benefits of IT enabled process changes: The result of the rebar batch production process (Value of potential savings)

The below simulation demonstrates possible cost-saving benefits related to repetitive construction process, reinforcing bar fabrication/assembly. According to the theory of parade of trades[9], resources produced by one trade are prerequisite to work performed by the next trade. This model shows that it is possible to reduce waste and shorten the duration by reducing the variability in workflow between trades. The assumptions applied in the process modeling are no error-rate, no rework over the whole process.

And, it is assumed that 100 tons of rebar are to be proceeded in the process. The numbers on each activity represent the number of outputs (ton): each activity always produce output 5 tons in one time unit (day). In case-I, considering the 3-day buffer-size in the warehouse to keep the fabricated rebar before delivering to the site, right after rebar fabricated at the fabrication yard accumulate in the warehouse to the amount of 15 tons, output 15 tons will be delivered to the site. Therefore, total number of execution day amount to 26 days under the given assumption.

If only considering labor cost, the total cost for this process from office to site amounts to 8,270 dollars.

In case-II, considering the 1-day buffer-size in the warehouse to keep the fabricated rebar before delivering to the site, total number of execution day amount to 24 days under the same assumption as case-I. The total cost amounts to 7,697 dollars.

In other works, under the same assumptions, the shortening the buffer size of warehouse induces cost saving of the amount of 573 dollars (8,270 – 7,697) comparing to case-I. From this, another case can be developed to get the additional cost saving. If the unnecessary activities are removed from the existing process, the cost saving impact should be obtained dramatically. Therefore, case-III was induced to demonstrate the cost saving benefits by process optimization.

Consequently, in the case-III considering the elimination of unnecessary process: reproducing the bar bending schedule and stockpiling the fabricated rebar which can be obtained by IT adoption, cost saving amounts to 3,827 (8,270 – 4,443).

In sum, these models just illustrated the limited process models. However, it is enough to demonstrate the possible cost saving benefits by the optimization of process in the existing rebar supply chain. However, to overcome many other possible cases, other approaches should be performed: e.g. probabilistic model.

1. Analysis of the readiness of the sector for implementation of the framework plan

In order to diagnose/analyze the practical state/readiness of reinforcement industry, surveys and site visits were performed during research. From this, we can understand the existing environment of reinforcement industry in the U.S.

5.1 Applied Systems Associates, Inc. (Software Firm)

5.1.1 The present state of IT adoption in the U.S. in the reinforcement industry sector

Mr. David A. Grundler, Jr., Vice President, Research and Design, aSa, mentioned that 75% of all North American Rebar Fabricators have, at least, some type of automated bar listing (data entry) and tagging system in use, with roughly half also utilizing automated Detailing and/or shop automation software.

5.1.2.According to his response, aSa software is currently installed at over 300 fabricating locations and over 150 AEC, Independent Detailing, and Independent Estimating sites.

5.1.3.aSa Software is a fully integrated suite of products designed to cover Estimating, Detailing, Fabricating, and Placing of rebar. Tasks typically done by the Rebar Fabricator. Although there are several design firms using aSa Software (primarily CAD/Detailing), aSa Software offers only minimal enhancements for the conceptual design and analysis of rebar.

5.1.4.Design firms using aSa Software have found benefits in detailing the rebar in-house at the same time or immediately following structural analysis and general reinforcing layout. Such firms feel that by doing the detailing, they have better control of the placing drawings, packaging, and delivery of steel from the fabricator, allowing them to expedite the entire process.

5.1.5.aSa estimates that roughly two thirds of all fabricated rebar in North America is processed through an aSa product: Supposing the total consumption of rebar in the U.S. amounts to 8 million tonnage a year, some 5.3 million tonnages of rebar a year are processed through this software.

5.1.6.With over 4,000 software users, aSa’s market share is probably somewhere between 70-80% of all firms using products similar to those offered by aSa.

5.1.7.Compatibility of Existing data

5.1.7.1.aSa Software currently has the ability to utilize data from external sources such as, but not limited to, AutoCAD and several ASCII file formats.

5.1.7.2.aSa Software is a fully integrated suite of products designed to cover Estimating, Detailing, Fabricating, and Placing of rebar.

5.1.7.3.Tasks typically done by the Rebar Fabricator. Although there are several design firms using aSa Software (primarily CAD/Detailing), aSa Software offers only minimal enhancements for the conceptual design and analysis of rebar.

5.1.7.4.Design firms using aSa Software have found benefits in detailing the rebar in-house at the same time or immediately following structural analysis and general reinforcing layout. Such firms feel that by doing the detailing, they have better control of the placing drawings, packaging, and delivery of steel from the fabricator, allowing them to expedite the entire process.

5.1.7.5.The most important factors for achieving the best practice in rebar information and supply.

5.1.7.6.Communication between the design community and the subcontractors (i.e.: rebar fabricator).

5.1.7.7.Without a doubt, the entire construction process could be expedited and duplication of duties could be greatly reduced if there were a more open exchange of information and ideas. Unfortunately, many in the design community are unwilling to furnish the subcontractors of a project even their basic CAD files, not to mention the supply of actual structural design data. Until such an open exchange occurs, software vendors developing applications that integrate design through construction have no market, therefore subcontractors must recreate what has already been done in order to serve their own trades.

5.1.7.8.Interestingly, the European philosophy over the years has been such that the designers also did the rebar detailing, furnishing fabricators with a material list. One would think that this would help expedite the process. Unfortunately, even in Europe the detailing responsibilities are becoming that of the rebar fabricator. The primary reason given is the fear of liability should a structural problem occur as a result of the reinforcing. Secondary reasons given are the often-limited time and budget constraints placed on designers and engineers.

5.1.7.9.Another, although related issue directly affecting the construction process is design constructability. Due to a multitude of reasons, many alignment conflicts, part and component incompatibilities, and unconstructible designs go undiscovered prior to erection. A common example would be the design of a column and supported beams reinforcing without consideration being given to the congestion at each components interference points, causing bars that have been fabricated according to design to be unusable at time of construction. Such a mistake can result in a several day setback in the construction schedule, as bars need to be redesigned and re-fabricated.

5.2Archer Western Contractors, Ltd.

5.2.1To diagnose/analyze the rebar process of general contractor, I contacted Archer Western Contractors, Ltd. and Mr. R. Scott Vann, Assistant Project Manager.

5.2.2Summary of practical project management in the site including rebar process

-Contract price = $ 20 million

-Concrete = 4,400 yd2 / Rebar = 345 ton

-Duration of Structural work = approx. 3 mths

-Avg. working days = 21 days/mth

-Productivity (Assemble) = 5.5ton/day

-Labor to assemble fab. rebar = 10-12m-day≒2 m-day/ton

-Unit rate of rebar: $429/ton (Fab.+Mat’l) + $190/ton (Assemble)= $619/ton

-Rebar Fabricator (Subcontractor): “Ameristeel”: B.B.S (reproduced by hand, neither AutoCAD nor other applications)

-Software in use: Document control: “Prolog”/Schedule control: “Primavera”/ Cost control: “their own S/W” & “Excel”

-Indirect labor: Avg. 3-4 persons/day

-Change order: is prepared by Subcontractors

-Staffs: 3 persons- PM(1), Assist PM (1), Admin (1)

5.2.3The below flow chart shows the process of rebar production. Main problem is there is no integrated management system in the supply chain. Having receiving drawing, rebar fabricator reproduced bar bending schedules as per the specification and drawings and submits them to architect/engineer for approval. Here’s main problem to cause the delay the schedule. It takes only 2-3days to fabricate the rebar after approval by architect/engineer. However, the duration for approval spends at least 2 times more than that of fabrication, delivery and assembly.

6Detailed plan for the next incremental step the reinforcement industry should take

6.1 From my study/analysis on the reinforcement industry chain, I reached the conclusion that integrated technology should be prior to the development/invention of new technology. According to my survey on firms regarding to rebar-related work, Software development firm and GCs, they have already adopted the Information technology more or less. However, they are so fragmentized that many information flows have not been integrated in the chains. In my opinion, there might be several steps that each reinforcement industry parties in chain should take: diagnose the current state of process flow; make a plan/vision for incremental progress toward optimization /rationalization; strong will of implementation, and so on.

6.2 How to do?[10]

6.2.1. Identify and attack primary causes of the quality, state, or degree of being variable or changeable

6.2.2. Cut down set-up times

6.2.3. Reduce processing durations: Eliminate, combine, or reduce

6.2.4. Design for continuous flow

6.2.5. Balance a production process in the supply/fabricationchain

6.3. Technologies and resources required for the next incremental step

6.3. The next steps the reinforcement industry should take

Briefly speaking, each party in the reinforcement industry should:

6.3.1. Use electronic exchange and sharing of rebar information. Initially this should take the form of standard formatted bending schedules

6.3.2. Adopt reinforcement detailing by contractors using integrated rebar detailing and manufacturing information.

6.3.3. Use bar-coding and text files as an automatic identification technique for the exchange of bills of quantities, test certificates, delivery notes and invoices: “Communication”

6.3.4. Use electronic transfers of information for the control of rebar bending and cutting machines.

6.3.5. The below table illustrates more detailed needs, technologies and resources required, and benefits to be achieved in short term in relation to each party.

Elements / Needs / Technologies & Resources Required / Benefits to be achieved in short term
Client & Main Contractor / Accuracy & transparency of information / Instant accurate reporting facility in ANY information /

1. Monitoring the rebar supply chain and managing the inventory
2. Reduce the project set-up time

Status report on Rebar-current situation / Quick and clear access to all data with powerful reporting tool
Quick implementation of changes / Any changes are electronically transferred across the entire rebar supply chain with instantaneous revision impact
Consultant Engineer / Fast and accurate creation of schedules / Intuitive schedule creation with validation to prevail local standards / 1. Fast communication between design parties and contractor
2. Reduce the error rate/re-work in the site
3. Lessen the fear of liability due to design failure
Compatibility with all major RC detailing S/W / Electronic receipt of data regardless of CAD type
Easy method of transmitting Rebar detail / Electronic transmission of data to subcontractor via e-mail
No process barrier to DWG/SKDL revisions / Schedules and revisions issued and updated in seconds
Contractor
/Subcontractor / Accurate and legible data / Electronic transmission of accurate data visible to all / 1. Shorten the time to reproduce the bar bending schedule
2. Balance a production rate in the supply/fabrication chain
3. Reduce the project duration
Quick visibility of schedules and changes / Instantaneous validation and revision process
Reduction in the manual process time / Major saving in manual process time with no re-keying of data
Avoid under or over ordering of reinforcement / Protect under or over ordering
Rebar manufacturer / Comprehensive and flexible production system / Powerful modular production system with options for optimization, mesh, invoicing, etc., which can be tailored to meet all production needs / 1. Able to fabricate the rebar automatically
2. Due to non-re-keying any data, reduce the fabrication time dramatically
3. Quick change of fabrication due to instant access to the design
Ability to forecast and plan accurately / Quicker visibility of accurate data with power reporting
Compatibility with existing systems / Designed to interface with existing production or back office system
Quick response to customer queries / Instant access to accurate data for rapid interrogation

7Conclusions

In repetitive process such as rebar fabrication, resources (equipment and labor) produce the work process and continue to move back and forth from one predecessor to another successor. In this repetitive cycle, the main issue for saving the cost is focusing on identifying and attacking primary causes of the quality, state, or degree of being variable or changeable, cutting down set-up times, reducing processing durations, designing for continuous flow and balancing a production process in the supply/fabrication chain. Comparing to other industry sectors, the market size of reinforcement industry is very huge. According to cost breakdown for rebar fabrication and assembly, the proportion of fabrication/assembly cost in the overall rebar work reaches to approximately 40 percentage. It means dramatic cost saving benefits can be derived from the optimization/rationalization of the existing process in rebar process chain. Considering the current amount of rebar consumption in the U.S is some 8 million tonnages, the further study on rebar process must be valuable field of research.