An integration of spreadsheet and project management software for cost optimal time scheduling in construction

Successful performance and completion of construction projects highly depend on an adequate time scheduling of the project activities. On implementation of time scheduling, the execution modes of activities are most often required to be set in a manner that enables in achieving the minimum total project cost. This paper presents an approach to cost optimal time scheduling, which integrates a spreadsheet application and data transfer to project management software (PMS). At this point, the optimization problem of project time scheduling is modelled employing Microsoft Excel and solved to optimality using Solver while organization of data is dealt by macros. Thereupon, Microsoft Project software is utilized for further managing and presentation of optimized time scheduling solution. In this way, the data flow between programs is automated and possibilities of error occurrence during scheduling process are reduced to a minimum. Moreover, integration of spreadsheet and PMS for cost optimal time scheduling in construction is performed within well-known program environment that increases the possibilities of its wider use in practice. An application example is shown in this paper to demonstrate the advantages of proposed approach

A conception of a new algorithm for the project time-cost analysis

The author presents again examples of activity-on-arcs networks already given in her previous contribution which revealed that in some cases the algorithm based on the critical path method with a time-cost analysis (CPM-COST) does not provide any optimal solution. The author also presents other defects of this method which have not been previously discussed. That is why, a new hand computational procedure for small projects is proposed. Its main assumption consists in taking into consideration, during the project acceleration, both critical paths as well as subcritical paths, the duration of which is longer than the desired project completion time. Additionally, the author puts emphasis on the fact that the project compression does not necessarily require that each critical path be shortened by exactly the same number of units. Sometimes other solutions are cheaper and just as efficient. The new technique is compared with existing heuristic and mathematical methods.CPM-COST, critical path method, time-cost analysis, crash time, (target) desired project completion time, algorithm, hand computational procedures, discrete approach, small projects

A pareto multi-objective optimization approach for solving time-cost-quality tradeoff problems

Speeding up a project's duration will definitely increase the cost and decrease the quality. The previous literatures were mainly related to project planning and controlling which mainly focus on cost-time tradeoff. However, limited researches have been referred to project quality based on mathematical methodologies. This paper proposes a tradeoff problem on time-cost-quality performance. A computer-based Pareto multi-objective optimization approach is utilized for solving the tradeoff problems. The approach can help searching near the reality Pareto-optimal set while not receiving any information on the stakeholders’ preference for time, cost and quality. Based on the developed approach, decision-making can become easy according to the sorted non-dominated solutions and project preferences

NEW COMPUTATIONAL RESULTS FOR THE DISCRETE TIME/COST TRADE-OFF PROBLEM WITH TIME-SWITCH CONSTRAINTS

Recently, time-switch constraints have been introduced in the literature by Yang and Chen (2000). Basically, these constraints impose a specified starting time on the project activities and force them to be inactive during specified time periods. This type of constraints have been incorporated into the well-known discrete time/cost trade-off problem in order to cope with day, night and weekend shifts. In this paper, we propose a new branch-and-bound algorithm which outperforms the previous one by Vanhoucke et al. (2002). The procedure makes use of a lower bound calculation for the discrete time/cost trade-off problem (without time-switch constraints). The procedure has been coded in Visual C++, version 6.0 under Windows 2000 and has been validated on a randomly generated problem set