Dominic Gallello - CEO, Graphisoft

Marcel Broekmaat - Product Manager, Vico Software

Clay Freeman - Chief Product Offocer, Vico Software 

 

 

The benefits of employing Virtual ConstructionTM are now very clear. The purpose of this paper is to summarize the main areas where the entire ecosystem of owners, architects, general contractors and subcontractors can expect to receive benefit from employing Virtual ConstructionTM techniques. The benefits can come in the following main areas:

 

The integration of design & estimating

The creation of cost calculations

The creation, analysis and optimization of schedules

Constructability analysis

Design to build/build to design processes

Risk reduction

Reduction in subcontractor costs

Management of contractual issues and claims

Winning more business

 

Design/Estimating Integration

 

Ultimately, cost drives design, however, the traditional tools do not provide sufficiently accurate and/or frequent information to make good decisions.

In current practice, architects are only provided with cost feedback after the construction company involved has reviewed the design, determined the quantities and assigned prices. During this process, the design effort continues, resulting in large amounts of rework in the case of a cost-driven design change.

 

Eric McKinney, CEO of Chong and Partners in San Francisco states that, "architecture is like driving with a blindfold on: upfront, you determine your target and, after driving for a while, you take off the blindfold and find out how close you got to the target".

The application of Graphisoft Virtual ConstructionTM products solves this problem by turning design and cost estimating into parallel processes.

In the new workflow enabled by Graphisoft products, Estimators work on cost Recipe definitions and Modelers design in parallel processes.

Using a data publishing mechanism, cost can be determined based on the information in the 5D model at any moment, immediately informing the design team of the cost consequences of design decisions. Costly rework can be avoided and improved support for an iterative design process will be realized.

Supported by an insight into the project design by means of the 5D model, which is based on the architectural, structural and mechanical (2D) drawings, the design process can now be managed more effectively and accurately.

In the early project phases, cost information will be assigned to the 5D model, based on historical data. These data will be available by means of Recipes that store this information and which are set up by a field engineer during and after an analysis of the company's knowledge base and processes.

The 5D model, resulting from converting the early phase design documents into an accurate 3D model linked to the Recipes, enables the performing of "what if?" scenarios on the design. Changes made to either the design (3D model) or the specifications (Recipes), can directly be analyzed using cost or tender report views in Graphisoft Estimator^TM. Any impact on the feasibility of the project of design changes proposed by the architect and engineers can thus quickly be analyzed.

Option tables allow performing "what if?" scenarios even more quickly, offering predefined sets of building component assemblies and applicable instances (e.g. door widths and finishing materials).

The 5D model will be upgraded during the design phases, and will include more specific data as the design progresses, resulting in cost estimates of increasing accuracy.

 

Creation of Cost Calculations

 

Every object in the 3D model is connected to an estimating Recipe that stores all the information required to carry out the cost estimation and scheduling of the specified object. Using this descriptive way of capturing "real world" objects, 3D models do not have to be highly detailed, thus saving modeling time.

When exact prices are not yet set, cost risks are included and identified by assigning cost variances in the Estimator cost estimate: optimistic and pessimistic price values for building components. Variance reports give a quick overview of the largest variances that may imply a cost risk to the project.

During the design process, more specific Recipes will replace the variance Recipes used in the early phases, reflecting the decreased price variance risk as the design work progresses.

"We have completed hundreds of projects with this technology and the results have been dramatic," stated Ilpo Jalasjoki, CEO of YIT Construction. "We have cut our project planning and cost estimating times by up to two thirds and have increased estimating accuracy. There are many other benefits that we have realized in our upstream and downstream construction processes."

 

Creation, Analysis and Optimization of Schedules

 

Planning production to flow continuously with synchronized production rates minimizes the likelihood of trades interfering with each other. There will be less wasted effort, idle time and fewer on-site conflicts. Graphisoft Control 2005 is a schedule planning and production control system that allows you to compress project schedules without increasing risk.

 

Schedule creation in Graphisoft Control is driven by material quantities that are derived from Estimator Recipes and 3D model quantity information.

Tasks can be defined by grouping materials and applying a production factor, after which the activity is displayed as a line. The angle of the line represents the production rate per location (units of material per time unit at a specific location of the project). Varying angles indicate different production rates and non-optimized scheduled tasks. The schedule can be optimized by "balancing" the lines: pacing the angles by assigning more optimized crew sizes and productivity rates.
Design updates are synchronized by simply re-importing the material quantities from Estimator.

Created schedules can be imported into the Constructor 5D model and simulated using Graphisoft 5D Viewer. Team meetings and subcontractor briefings can be carried out more effectively by using this simple insight tool, thus ultimately allowing clients to benefit to a larger extent from valuable subcontractors' feedback.

Improved control of the progress of the work project can be achieved by using task management functionality - actual information is reflected in the original schedule. Anticipated construction errors resulting from the progress made are flagged as warning signs.

 

An example is a €4 million/4,000m2 university building project, managed by NCC Construction.

The original schedule was planned with typical CPM-based software. The problems were then analysed in Graphisoft Control revealing inefficient use of time and subsequent risks. Problems such as an unsynchronized schedule, uneven start ups, uneven durations and many tasks in the same locations were clearly highlighted in Graphisoft Control Advanced Line-of-Balance, which combines a project's locations, time and activities (work crews) on one screen. The schedule was streamlined, resulting in better use of time, more synchronized critical activities and a more implementable schedule.

 

Benefits:

A cut in project duration of 8 weeks

A weekly reduction in overhead costs of €5,000 (management, electricity and heating of facilities)

A 30% decrease in resources

Winning the next (€15 million) project, despite submitting the highest bid, because NCC could demonstrate the best plans and methods

 

Constructability Analysis

 

Graphisoft ConstructorTM is used to create an accurate 3D model. By enabling the creation of a model sufficiently accurate for construction analysis, many of the errors common in construction projects can be eliminated during the design phase.

• The creation of the 3D model enhances trade coordination, supports estimating as a parallel process and serves as the primary connection point for downstream applications.

For the George Lucas new corporate campus in the Presidio , at the foot of the Golden Gate Bridge, in San Francisco, a construction model was created from a set of 2D drawings to help to communicate to the general contractor and the subcontractors exactly what needed to be built. How successful was it? To quote Tom Brady, who was the construction manager and was speaking at the ASC Construction Management Conference in February 2004, "I believe that in five years, every major project will employ a building model". Kajima in the UK has also taken 2D drawings and turned them into a 3D construction model. The result? - The elimination of many coordination problems, delivering a saving of £250,000 on the project.

 

Design to Build/Build to Design Processes

 

The analysis options offered by Graphisoft Virtual ConstructionTM products make it much easier to spot potential problems earlier in the design process, when they can be corrected cheaply.

In the Design to Build process, a model, accurate for construction purposes, is created. This model reflects the actual construction techniques that will be used on the project. Additionally, acceptable tolerances are defined for each modeled item. The model is analyzed according to the defined tolerances and not just to the exact placement of the objects in the model. This process ensures the proper coordination of all trades, without forcing subcontractors to work at an impractical and costly level of precision.

In the Build-to-Design process, key points are extracted from the model and fed into a laser or other form of measurement system and it is then verified that they are within the tolerance defined in the model. By verifying that subcontractors are working within the tolerances defined in the model, the construction management team ensures that prefabricated elements, yet to be installed, will fit.

These new work practices involve better reuse of design data, more extensive prefabrication, and even new construction techniques that would not be practical without the precision provided by the process.

 

Risk Reduction

 

There are two main contributors to risk:

Incorrect information caused by the lack of time to effectively synchronize all data related to project design, cost and time

Incorrect assumptions generated by the variability of conditions during actual construction

The Virtual ConstructionTM solution addresses these problems in a number of ways:

Design information is more accurate and comprehensive.

The synchronization of design, cost and time data is automatically maintained at all stages of design and construction by Graphisoft Constructor.

More effective analysis techniques, using Line-of-Balance, Monte Carlo simulations and 4D can be affordably and practically employed. 4D technology clearly shows the construction sequence by means of a color- and texture-coded 3D model. The 4D model offers functionality for gaining quick insight into a schedule, as well for identifying time/space conflicts, i.e. conflicting construction activities taking place at the same time at the same location.

Graphisoft Control's Monte Carlo risk simulation allows for the checking of project schedules by assigning optimistic and pessimistic start and end variances to activity definitions, which are then calculated >1,000 times by the software. Conflicts are graphically flagged using warning signs in the Line-of-Balance display and can easily be interpreted and followed up.

The production analysis and control tools allow the project team to constantly monitor, analyze and respond to conditions throughout the project.

The sum of these benefits provides a far more effective decision support framework than traditional processes.