Computerised tool for hierarchical simulation modeling

Advancements in computing have enabled the development of effective tools for the modeling and analysis of construction operations. In particular, recent developments in object-oriented and event-driven programming were used by the writers in the development of a hierarchical, modular, and graphical environment for simulation-based planning of construction projects. This system, termed hierarchical simulation modeling (HSM) method, is specifically geared toward modeling the uncertain nature of conditions under which projects are implemented and the dynamic utilization of resources in construction. The modeling concepts, internal structure, implementation, and working of this environment are described in this paper. ''Model definition,'' ''translation,'' ''simulation,'' and ''report generation'' are the four internal modules of this system. One of the key concepts highlighted in this paper is the use of an object-oriented paradigm for developing modeling objects that have ''graphics'' and ''simulation'' properties that allow development of an interactive graphical simulation modeling environment

Hsm-Simulation-Based Planning Method For Construction Projects

Construction projects are characterized by the random nature of the conditions under which they are implemented and by the dynamic use of available resources. Since site conditions vary randomly and resources perform a multitude of functions on various work tasks, planning of construction projects using traditional tools like the critical path method becomes limited and induces deficiency in the resulting plan. This paper demonstrates that a simulation-based methodology is appropriate for modeling such a scenario. The hierarchical simulation modeling (HSM) method, a simulation-based method, for planning of construction projects is presented, HSM enhances and combines the concepts of work breakdown structure and process modeling to arrive at an advanced framework for planning. Hierarchical and modular simulation constructs form the basis of this method. The construction of a bridge (Peace River Bridge) is used to illustrate HSM concepts and its advantages

Subjective And Interactive Duration Estimation

Scheduling of construction projects with an uncertainty content requires that the scheduler's subjective knowledge of various factors that might influence the duration of the activities comprising the project is incorporated. Depending on the participating factors and their significance, a different duration outcome is often observed for each activity. To include this uncertainty in the schedule, a statistical distribution is frequently used. This paper presents a system based on the premise that part of the information available, when duration distribution is being estimated, exists in a subjective form. We present an automated system that requires the modeler to specify the activity's minimum and maximum times and a set of linguistic descriptors of the external factors that are suspect of influencing the duration. The lower and upper end point estimates are often available from familiarity with the technology used, physical and logical constraints, or a combination of these situations. The subjective information collected by the modeler is modeled as fuzzy parameters and is quantified using fuzzy set theory. The result of the fuzzy set analysis is a sample of activity durations from the underlying distribution, which is then used to characterize the first two moments of that distribution. Since earlier research has shown that the beta distribution provides an adequate representation for construction durations, the end points specified by the user and the two moments resulting from the fuzzy set analysis are used to fit a beta distribution. The system then allows the user to visually assess the quality of the fit and modify the shape of the beta density using the visual interactive beta estimation system. The paper also presents a practical construction scheduling application to demonstrate the use of the developed system

Construction project simulation using CYCLONE

Construction simulation is a powerful tool that can be used by a construction company for a number of tasks such as productivity measurement, risk analysis, resource planning, design and analysis of construction methods, and site planning. The success of simulation at the construction-process level has led to a natural attempt to use simulation at the construction-project level. Cyclic Operations Network (CYCLONE) and related simulation methodologies have provided the fundamental basis of these developments. This paper describes the enhancements made to the CYCLONE modeling methodology to allow simultaneous simulation of processes involved in a construction project. The objective of these enhancements is to allow development of individual models for all the processes that constitute a project and then to link them so as to simulate them simultaneously using a common resource pool. Such a simulation experiment will allow the construction manager to realistically model, analyze, and plan construction projects. This paper provides the specifications required to perform a project-level simulation using the CYCLONE modeling concepts

La Productivit\ue9 dans la construction

Written for project engineers, superintendents and foremen, Productivity in Construction provides a comprehensive overview of the factors that affect productivity. The document addresses a wide range of micro-related productivity issues (i.e. those that construction practitioners can influence directly as opposed to macro-issues such as government regulation and research and development investment) and provides a framework to improve on-site construction productivity. You will find sections on measuring and improving productivity at construction sites and on recognizing the impact that human factors such as motivation, learning curves, overtime, experience, and absenteeism have on productivity. The importance of competent, professional management is also addressed.Con\ue7u \ue0 l'intention des ing\ue9nieurs de projet, des chefs de chantier et des contrema\ueetres, La productivit\ue9 dans la construction trace le tableau des facteurs qui influent sur la productivit\ue9. Le document examine \ue0 fond les questions de micro productivit\ue9 (c.-\ue0-d. celles sur lesquelles les entrepreneurs exercent un contr\uf4le direct, \ue0 l'oppos\ue9 des questions de macro productivit\ue9 comme la recherche, les r\ue8glements gouvernementaux et les investissements en d\ue9veloppement) et propose un cadre de travail pour am\ue9liorer la productivit\ue9 des chantiers. Le lecteur y d\ue9couvrira comment mesurer et accro\ueetre le rendement, et comment tenir compte de facteurs humains tels que la motivation, les courbes d'apprentissage, le temps suppl\ue9mentaire, l'exp\ue9rience et le taux d'absent\ue9isme. La publication souligne \ue9galement l'importance de faire appel \ue0 un personnel professionnel et comp\ue9tent.Also available in English: Productivity in ConstructionPeer reviewed: NoNRC publication: Ye

Integrating theory of inventive problem solving into the Value Engineering process

Value Engineering (VE) is traditionally a process aimed at achieving cost effectiveness for a product, project or system based on brainstorming and other freethinking techniques. This traditional VE process often lacks focus on the problem, and as a result, many alternatives generated in the VE process are not relevant to the problem and consequently useless. In addition, this process may not be able to enhance the value due to lack of direction in problem-solving. To overcome these problems, this paper has improved the VE process by incorporating some of the useful tools of the theory of inventive problem solving (TRIZ) into the creativity phase of the traditional VE exercise in order to guide the brainstorming and freethinking toward effective and efficient generation of "focused" ideas toward achieving the best and final solution. © 2008 Taylors Francis Group