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09:00   General Paper Session W65 - Innovation in construction (theories and best practices)
Chair: Martin Sexton
09:00
15 mins 		System-search SCHEDULING PROCESS: USING ONE-DAY SCHEDULING ON MULTI-FAMILY PROJECTS TO REDUCE DELIVERY TIME
Bruce Smith
Abstract: The past fifty years has seen many changes in the construction process, but little has changed in the area of scheduling for most projects. There have been advances in the software used to manage schedules, but the same theories and practices that have been used for decades continue to be used. Activities are identified, defined, assigned durations, and linked by relationships to create a work flow through the project that is effective and manageable. This process works well and will continue to be norm on most projects. Some home builders have incorporated a process “one-day scheduling.” The process views the project as a linear sequence of days and identifies what activity is start and finish on that day. Several large home builders have found that the number of calendar days to construct an individual home as part of a large development has been reduced significantly, giving them a strategic advantage in the market. The following study looks at the implementation of a combination of traditional and “one-day scheduling” on multi-family residential projects as a method of schedule management, resource management, and cost control. The study schedules both vertical and horizontal projects. The study reviews the management of the schedule during construction as well as the scheduling process. The end goal of any construction project is to deliver a project of the greatest value to the owner for the defined cost. The implementation of a method of scheduling which delivers a product more efficiently will conserve resources and enhance the goals of sustainable construction.
09:15
15 mins 		System-search A PHASED CITY ENERGY PLATFORM FOR NETWORKED PRECINCT BUILDINGS IN THE CONTEXT OF MANAGEMENT INFORMATION SYSTEMS AND SMART GRIDS
Tom Barker
Abstract: This research investigates the context and advantages of energy sharing between networked precinct buildings in the context of pre-existing urban stock. The paper considers whether the sharing of patterns of use and knowledge of buildings’ spatial, architectural and energy-related components can act as a phased prequel to energy sharing and provide a ‘knowledge pool’ to facilitate changes to the technological mix in a building, as well as modes of usage. In the context of energy use and conservation it is well understood that resource sharing can be advantageous across multiple buildings, but less is known about the potential benefits of energy knowledge sharing across buildings. The sharing of energy data across buildings with different owners/operators but offers the advantages of balancing demand across facilities, right-sizing technology components, intelligent planning and future usage pooling – particularly for smart buildings with energy storage and generation capacity. With a focus on the Australian context, this research investigation examines how an initial energy information platform phase could benefit a range of building stakeholders and be lead to a subsequent energy sharing phase. The author argues that there is value in a city energy information platform as a prequel to smart grids and subsequently as a complement to smart grids.
09:30
15 mins 		System-search APPLYING THE SHUFFLED FROG-LEAPING ALGORITHM TO IMPROVE SCHEDULING OF CONSTRUCTION PROJECTS WITH ACTIVITY SPLITTING ALLOWED
Mehdi Tavakolan, Baabak Ashuri, Nicola Chiara
Abstract: In situation of contractors competing to finish a given project with the least duration and cost, acquiring the ability to improve the project quality properties seems essential for project managers. Evolutionary Algorithm (EAs) have been applied as suitable algorithms to develop the multi-objective Time-Cost trade-off Optimization (TCO) and Time-Cost-Resource Optimization (TCRO) in the past few decades ; however, by improving EAs, the Shuffled Frog Leaping Algorithm (SFLA) has been introduced as an algorithm capable of achieving a better solution with faster convergence. Furthermore, considering splitting in execution of activities can make models closer to approximating real projects. One example has been used to demonstrate the impact of SFLA and splitting on the results of the model and to compare with previous algorithms. Current research has elucidated that SFLA improves final results and splitting allows the model find suitable solutions.
09:45
15 mins 		System-search RELEASING THE POTENTIAL OF BIM IN CONSTRUCTION EDUCATION
John Boon, Chris Prigg
Abstract: BIM at least in the sense of 3D modelling is fast becoming a reality in the commercial world. It also has the potential to become a powerful tool in the world of construction education. At its simplest it enables construction students to see in a 3D virtual model how buildings are assembled. This in itself is a considerable advance on trying to get students to learn building construction through interpreting 2D information. Beyond this BIM has the potential to allow faculty to radically rethink the teaching and learning process for construction students. If the BIM models provide information, that is readily understood by the student, as to how buildings are assembled, faculty should be able to spend less time “telling” students about construction detailing and thereby create more time for the students to learn by interacting with BIM models in the processes of construction planning, measurement and estimating. The paper revisits education theory with a focus on how students learn by “seeing” and “doing” rather than “listening”. It then explores how that theory can be combined with the potential of BIM to give the students enhanced learning experiences. A case study of early attempts to unlock the potential of BIM in a construction education setting is presented.
10:00
15 mins 		System-search HEURISTIC SOLUTION FOR RESOURCE SCHEDULING FOR REPETITIVE CONSTRUCTION PROJECTS
Marco A. Bragadin, Kalle Kahkonen
Abstract: Construction project planning and control are core processes for building project management. In practice project time management is achieved by computer based techniques like Precedence Diagramming Method (PDM). PDM is a network-based planning instrument where building processes are represented topologically by means of an activity network. This is called Activity-Based Scheduling: activities, set of working operations performed by resources i.e. crews, are linked with each other by logical dependencies. Activity network is a time oriented building process model that provides construction planning. Time flow is modeled through the network by performing critical path calculation. Resource flow through project activities is not modeled in a direct way, i.e. resources are simply loaded to corresponding activities as an attribute or a label. Networking techniques represent the state of the art of construction project planning and scheduling in real life projects, but many researchers and practitioners claims that these techniques do not provide a suitable model for construction process, especially in repetitive projects. This is mainly because activity network is discrete while construction process is basically a continuous flow of working operation performed by specialized resources. A repetitive project is a multi–unit project where resources move through the various similar location of the project (e.g. multi – storey building, housing projects, highway projects), while a non-repetitive project is a building project that has a complex location breakdown structure and is mostly a set of one-off activities. Construction process modeling, for repetitive projects in particular, needs a more accurate model for resource flow through project activities. Location Based Scheduling is a resource oriented construction process model. In Location Based Scheduling working tasks, set of repetitive activities, are plotted on time / space chart using general principles of the Line of Balance (LOB). The essence of location based resource scheduling is the view of the movement of construction resources through the various project locations as a key to improve project performance. With the aim of improving resource scheduling in repetitive construction projects with Precedence Diagramming Method, an heuristic algorithm for repetitive activity scheduling process is presented (REPNET), based on a precedence network plotted on a resource–space chart. In repetitive-unit projects it is important that repetitive activities are planned in such a way as to enable timely movement of crews from one repetitive unit to the next, avoiding crew idle time. This is known as the “work continuity constraint” and its application during project planning can provide an effective resource utilization strategy that can lead to: maximization of the benefits from the learning curve effect for each crew; minimization of idle time of each crew; minimization of the off-on movement of crews on a project once work as begun. The heuristics of REPNET carry out resource timing in two phases: in the first phase as soon as possible project schedule is performed; in the second phase the REPNET algorithm search for resource scheduling optimization by minimization of resource idle time in repetitive activity performance. The work continuity constraint is relaxed in order to maintain the PDM minimum project duration. In this way, besides the classic time critical path, a resource critical path is detected. Space critical path can be highlighted if useful. The REPNET optimization algorithm is performed for a case study, the Galli Theatre refurbishment project, and flow-line view on a time – space chart is also plotted to verify project feasibility. Optimized project schedule is compared with original network scheduling and discussed.
10:15
15 mins 		System-search FOSTERING AN ENVIRONMENTALLY RESPONSIVE INDUSTRY – A PUBLIC SECTOR CASE STUDY FROM HONG KONG
Gangadhar Mahesh, Mohan Kumaraswamy, Yang Pu, Bo Xie
Abstract: Well meaning high-level construction industry reviews, and recommendations from those reviews, usually lead to many industry development initiatives. Promoting a safer work place and environmentally responsible industry was one of the seven themes under which recommendations were made in Construction Industry Review Committee (CIRC) Report of 2001 of Hong Kong. These were followed with many related initiatives for industry development by industry stakeholders. The findings reported here are part (limited in focus to environmental responsiveness of construction industry) of a wider research project titled ‘Construction Industry Development Comparison and Acceleration’ (CIDCA) designed to track implementation programmes against the original objectives in the CIRC report and some changing priorities thereafter, actual achievements, drivers, enablers and barriers, residual issues and concerns; in comparison with UK and Singapore scenarios in interlocking studies. The original CIRC recommendations laid the responsibility of promoting an environmentally responsible industry on public sector agencies with an assumption that the private sector would follow suit. In this regard, a case study of a proactive public sector client was conducted. The data from the case study was supplemented with interviews with key personnel from other stakeholder organisations. The findings reported here identify environmentally responsive initiatives from the case study and isolate high impact initiatives among them. Their implementation is tracked and their impact on the rest of the industry is analysed. Also, key challenges and enablers/ barriers are identified in terms of achieving (i) desired results within the organisation and (ii) desired impact on the industry. Lessons learnt are then discussed with an emphasis on transforming innovative initiatives into acceptable industry norms. The reported findings though specific to the Hong Kong Construction Industry should provide pointers on implementing public sector led initiatives for other countries.
10:30
15 mins 		System-search CM-AT-RISK AS A HIGHWAY CONSTRUCTION DELIVERY SYSTEM IN THE SOUTHEASTERN UNITED STATES
Edward Minchin Jr., Xiao Xiao Li
Abstract: State Highway Agencies (SHAs) in the United States discovered long ago that construction delivery systems used by the vertical construction industry could be successfully adapted to highway and bridge work. The main benefit that the SHAs were seeking was less time between project conception and project completion. The adoption of Fast Track contracting methods like Design-Build (DB) and all its sub-systems like Design-Build-Operate, Design-Build-Operate-Transfer, etc. fulfilled the promise of a shorter project duration than the SHAs were accustomed to under the traditional Design-Bid-Build delivery system. However, the newfound speed came at a cost. Not a financial cost, but a cost that SHAs are increasingly interested in eliminating. The cost is the loss of control over the design process. In most Fast Track delivery systems, including all of the DB family of methods, there is no contractual relationship between the design firm and the SHA. This often leads to uncomfortable situations for the SHA. Of course there is always the danger that the contractor and the owner will conspire to deceive the SHA when something goes wrong. Certainly there is the temptation for the designer to tell the SHA that some “problem” with the construction discovered by the SHA was built “as the designer intended” because any cost incurred by the contractor to correct the problem is money lost by the designer as party to the joint venture or whatever agreement has forged the designer and the contractor into one entity. Even if the contractor and designer are of high character and do not set out to deceive the SHA, sometimes they can find something wrong with the project as constructed and set out to fix it without telling the SHA. Even if the failure to tell the owner about the problem is an oversight due to a sincere effort to fix the problem as quickly as possible, the SHA is in the unenviable position of not knowing what is happening on their own project. Now, SHAs are looking for a way to keep the speed of a Fast Track contract while retaining the control over the design process that they have in the DBB contract. Many SHAs are looking to Construction Manager-at-Risk (CMR) as the solution to the problem posed by the question “how do we retain the speed of Fast Track contracting while retaining the control over the design process offered by the DBB delivery system? This research project included interviews with of all the SHAs and other relevant public transportation agencies in the southeastern United States (11 states). Each agency interviewed was asked if they had ever used CMR, or had plans to. If they answered in the affirmative, they were asked a series of questions about the project. If the project seemed especially important or interesting, the research team visited the project for a week, conducting face-to-face interviews with personnel with the construction manager, top-tier subcontractors, sub-subcontractors, design professionals, suppliers, owners, and consultant inspectors. The results of the interviews and case studies are reported in this paper.
10:45
15 mins 		System-search CONSTRUCTION SCHEDULING WITH IMPRECISELY DEFINED PLANNING CONSTRAINTS
Janusz Kulejewski
Abstract: The problem undertaken in this paper regards to the scheduling of construction project under imprecisely defined limits of time and resources available for the execution of works. A single-point network model with finish-to-start relations between activities is adopted to represent the course of construction. Durations of works take into account the expected effects of possible interference (bad weather, equipment failures, etc.). The paper presents the principles of modeling imprecisely defined planning constraints using trapezoidal fuzzy numbers and the principles of assessing compliance with fuzzy restrictions using possibility theory. A probabilistic approach in conjunction with the concept of -cuts of fuzzy numbers is proposed for the neutralization of assessments to meet the fuzzy constraints. The paper also presents a numerical example showing the advantages of the use of probability measure to optimize the construction schedule in the terms of imprecisely defined planning constraints.
11:00
15 mins 		System-search THE TIME-COST ANALYSIS OF THE CONSTRUCTION PROJECT, TAKING INTO ACCOUNT RISK BASED ON EXPERT KNOWLEDGE USING FUZZY SETS
Andrew Minasowicz, Bartosz Kostrzewa
Abstract: Main goal for presented analyze is the detailed review of risks, connected with relevant project, before the “go” decision is made, at the pre-feasibility stage. Project cost and time deviations (for relevant tasks) were established for the schedule and cost estimation with use of the fuzzy set theory and experts knowledge. Set of information – based on experts knowledge was transformed with use of the fuzzy sets theory. Elements of the model are: fuzzyfication block (for fuzzyfication of data), inference block (for making conclusions) and de-fuzzyfication block (for sharpness of results). Model allows for automatic creation of different scenarios for the project (with use of non complicated math, like average value or mass extentricity) – pessimistic and optimistic scenarios for the investment, both from cost and time points of view. Authors present final results – value of risk, connected with time and costs of the project, which are function of standard deviation and probability of the risk appearance. Assessment of the risk for the whole investment is the aggregate results calculated for the particular tasks of the investment. Model allows for comparison of – for example - different technologies and choice of the optimal variant.