Network Scheduling Techniques Research Articles

A new perspective in construction management; the metaverse

A conceptual construction management model can be applied to the metaverse 3D technology in this study, which demonstrates how accelerated back-and-forth replays of the construction process can be used to evaluate the impact of new decisions on the project. Participants in the proposed model will be able to see exactly how their decisions during construction affect the progress of the project. In order to develop this model, three phases are required: 1) Analyzing the problem and planning the algorithm, 2) collecting data and designing the hybrid model utilizing artificial intelligence and construction network scheduling techniques, and 3) coding the algorithm. The design-based research will contribute to the development of new meta-models for construction management, present innovative ideas for students, engineers, and managers working in the field of construction management.

Sixty years of project planning: history and future

Abstract Modern project management owes its reputation to the development of modern scheduling techniques based on the theory of graphs, namely, network scheduling techniques. In 2017, these techniques are celebrating their 60th birthday. This anniversary provides the opportunity to look back at the most important achievements such as non-linear activities and new precedence relations, as well as to take a look into the future. The highlights of this subjective retrospective are the presentation of the latest results and the compilation of those problems that will probably define the priorities for future research. This paper is the extended version of the keynote lecture/presentation that has been presented at the PBE 2016 Conference (People, Buildings and Environment, Luhačovice, Czech Republic) (Hajdu 2016a).

Project cash flow analysis in the presence of uncertainty in activity duration and cost

The inherent uncertainty and imprecision in project scheduling have motivated the proposal of several fuzzy set theory based extensions of activity network scheduling techniques. Building upon these, a cash flow calculation methodology for projects including activities with fuzzy durations and/or costs is proposed in this paper. According to the proposed approach, the project cash flow is represented by an S-surface (as opposed to the traditional S-curve) ensuing by connecting S-curves at different risk possibility levels. The methodology is exemplified by estimating the working capital requirements in a real world road construction project. Furthermore, the benefits of the methodology and its subsequent computerization are discussed. It is believed that the proposed approach may also be useful for both evaluating project proposals during feasibility studies and for performing earned value analysis for project monitoring and control.

Simulation-Based Auction Protocol for Resource Scheduling Problems

Resource scheduling, or the allocation of resources over time, is a challenging problem in large-scale or multiple-project environments. Traditional network scheduling techniques are ineffective in modeling the dynamic nature and resource interactions of large or multiunit projects. This paper presents a simulation-based auction protocol (SBAP) to solve resource scheduling problems in large-scale construction projects. SBAP is a hybrid framework that integrates multi agent resource allocation (MARA) in a simulation environment. SBAP deploys a centralized resource allocation approach, referred to as an auction protocol, whereby agents bid on different combinations of resources at the start of a simulation cycle. Agents attempt to improve their individual welfare by acquiring a combination of resources; an auctioneer looks at the entire system and allocates resources to the agents using a combinatorial algorithm to maximize an overall objective function (e.g., maximizing the system’s revenue or minimizing t...

Optimizing Resource Leveling in Construction Projects

Construction schedules, generated by network scheduling techniques, often cause undesirable resource fluctuations that are impractical, inefficient, and costly to implement on construction sites. This paper presents the development of two innovative resource leveling metrics to directly measure and minimize the negative impact of resource fluctuations on construction productivity and cost. The first metric quantifies the total amount of resources that need to be temporarily released during low demand periods and rehired at a later stage during high demand periods. The second measures the total number of idle and nonproductive resource days that are caused by undesirable resource fluctuations. The two new metrics are incorporated in a robust and practical optimization model that is capable of generating optimal and practical schedules that maximize the efficiency of resource utilization. An application example is analyzed to illustrate the use of the model and demonstrate its capabilities. The results of this analysis show that the present model and metrics are capable of outperforming existing metrics and eliminating undesirable resource fluctuations and resource idle time.

Network Resource Allocation with Support of a Fuzzy Expert System

Critical path method and program evaluation and review technique (CPM/PERT) without resource allocation are totally inadequate for control of major projects. Resource allocation has been a major concern of research and actual application development since the advent of the CPM/PERT network scheduling techniques. Many algorithms have been developed including theoretical optimization and heuristic rules since early 1960. The theoretical approaches generate too many combinations and are, therefore, quite expensive to use. The heuristic approaches provide a reasonable solution to the “too expensive” problem. However, none of these algorithms has the capability to resolve the impacts of a variety of external forces, such as weather conditions and resource availability, that are unavoidable in any real‐life project. This paper proposes a practical algorithm to implement resource allocation. The proposed algorithm uses the output from an expert system called priority ranking, which uses possibility theory and the generalized modus ponens logic inference rule to determine the priority ranking. In addition, both network‐related and project‐related factors are included in the algorithm.

Time Space Scheduling Method

A construction scheduling technique is presented which is, in many cases, more advantageous than bar charts and network schedules, particularly for repetitive activities and for scheduling the work in sections of a project (floors, bridge spans, road and sewage sections, etc.). The technique is labeled the time space scheduling technique because it shows clearly the connections of activities, their duration times, and sections (space) where they take place in a given time. The principal organization of the construction process is described. Examples of the application of time space scheduling are given for the pump foundation in a pipeline, construction of an apartment house, a multistoried concrete building, a road section, and a railway bridge. The time space scheduling technique is compared to bar charts and network scheduling techniques. Advantages and limitations are examined.