This paper concludes that 4D models are a useful alternative to project scheduling tools like CPM networks and bar charts. They enable more people to understand a schedule quickly and identify potential problems. By developing a 4D model for a commercial construction project, we were able to detect the incompleteness of the original schedule, find inconsistencies in the level of detail among the schedule activities, and discover an impossible schedule sequence. We were also able to anticipate potential time-space conflicts and accessibility problems. The results of the case study show that 4D models are effective in evaluating the executability of a construction schedule. The case study also highlighted the need for improvements to 4D tools. 4D tools should include bar charts, component lists, and annotation tools in their graphical user interface. Automating schedule data preparation and 4D model generation in the design stages of a project can expedite 4D model development and use. Users need to be able to generate 4D models at multiple levels of detail and generate and evaluate alternative scenarios rapidly.

Closure of "Feasibility Study of 4D CAD in Commercial Construction"

Enhancing environmental sustainability over building life cycles through green BIM: A review

Research trends and opportunities of augmented reality applications in architecture, engineering, and construction

Many construction processes include installation of unique materials in specific locations in the facility being built: materials and locations must match before installation can take place. Mismatches due to delay and uncertainty in supplying materials or completing prerequisite work at those locations hamper field productivity. This is illustrated here using a model of a materials-management process with a matching problem that typifies fast-track process-plant projects. The uniqueness of materials and locations combined with the unpredictability in duration and variation in execution quality of various steps in the supply chain allow for different ways to sequence material delivery and work area completion. Several alternatives are described. Their impact on process execution is illustrated by means of probabilistic process models. One model reflects total lack of coordination between delivery and work area completion prior to the start of construction; a second one describes perfect coordination. The corresponding materials staging buffers and construction progress are plotted based on output from discrete-event simulation models. A third probabilistic model then illustrates the use of the lean construction technique called pull-driven scheduling. Real-time feedback regarding the status of progress on site is provided to the fabricator off site so process steps can be re-sequenced opportunistically. This yields smaller buffers and earlier project completion and, when properly accounted for, increased productivity.

Pull-Driven Scheduling for Pipe-Spool Installation: Simulation of Lean Construction Technique

Real-time resource location data collection and visualization technology for construction safety and activity monitoring applications

Stroboscope: State and resource based simulation of construction processes.

This paper examines the characteristics of discrete-event simulation systems in terms of their application breadth (general or special purpose), modeling paradigm (process interaction versus activity scanning), and flexibility (programmable or not). Several construction simulation systems are examined with primary emphasis on CYCLONE and STROBOSCOPE as representatives of the wide range of tools that are currently available. CYCLONE is a well-established, widely used, and simple system that is easy to learn and effective for modeling many simple construction operations. STROBOSCOPE is a programmable and extensible simulation system designed for modeling complex construction operations in detail and for the development of special-purpose simulation tools. The characteristics of these systems, as well as other recent developments, illustrate that an effective general-purpose simulation tool for construction is in essence one based on extended forms of activity cycle diagrams and the activity scanning modeling paradigm. As explained through several examples, these representations are indeed the most convenient and intuitive for construction simulation systems. Furthermore, the programmability of such a system is the principal factor that determines its power, flexibility, and ease of learning and use.

General-purpose systems for effective construction simulation

Simulation modeling and visualization can substantially help in designing complex construction operations and in making optimal decisions where traditional methods prove ineffective or are unfeasib...

Visualizing Simulated Construction Operations in 3D

Stroboscope is a programming language designed for the simulation of processes common to construction engineering. These processes are very complex and involve many different types of resources. As a result, Stroboscope is also an efficient and effective general purpose simulation system. The paper presents an overview of Stroboscope and illustrates how it can be used to model a complex example taken from classic simulation literature.

General purpose simulation with stroboscope

This paper suggests the methodology to follow when conducting discrete-event simulation (DES) studies in construction engineering and management research. Emphasis is made on the steps that, due to the uniqueness of the construction environment, are particularly important yet are not discussed extensively in the general DES literature. Guidelines are provided to determine what aspects of a DES study demand a rigorous application of the theory depending on the purpose of the study. The paper concludes with the importance of properly understanding the probabilistic concepts upon which DES relies and on coupling this understanding with engineering judgment as a key for successful use of DES in construction research.

Julio C. Martinez

Papers

Stroboscope: State and resource based simulation of construction processes.

General-purpose systems for effective construction simulation

Visualizing Simulated Construction Operations in 3D

General purpose simulation with stroboscope

Methodology for Conducting Discrete-Event Simulation Studies in Construction Engineering and Management