Network Planning

Revision as of 10:32, 20 February 2021

Abstract

The success of a project's realization depends heavily on the effectiveness of the planning phase. This article will present how to use network planning in project management, which can be very challenging, and requires careful planning, managing, and controlling. The ability to break down work and segment it into different assignments can be critical for project success. Having a comprehensive plan can explain the project's complexity and keep it on track ^[1]. Network planning is a common term for methods where projects are studied as a series of interrelated activities to plan, manage, and control projects ^[2].

According to Guide to the Project Management Body of Knowledge, project schedule management includes various processes required to manage the project's timely completion. These processes refer to, among other things, how to sequence activities and estimate activities duration. Moreover, they include developing and controlling the schedule. Network planning methods help in this processing. The main objectives of network planning are determining the project duration and the Critical Path. Moreover, find out how to speed up a project if that becomes necessary. As a result, it is a basis for scheduling ^[3].

The most well-known network planning techniques are the Critical Path Method (CPM) and the Program Evaluation and Review Technique (PERT). These methods include describing each of the activities involved in the project, the order in which must carry out the activities, and the activities carried out in tandem with other activities. Using network planning methods results in showing activities that can be completed simultaneously and increases efficiency. Moreover, it helps in decisions making and saves time, and therefore decreases cost. Conversely, creating it uses merely estimates, which may be inaccurate. Furthermore, large scale projects are often complex and detailed, and thus performing network planning on them, can be time-consuming ^[2].

The focus of this article will be introducing network planning and describing different methods of it. Moreover, identify how to apply network planning techniques to project management and choose the right method for various projects. Finally, this article will describe the limitation of network planning.

Why Use Network Planning in Project Management?

History

Network planning methods were first developed in the late 1950s. The most known network planning techniques are the Program Evaluation and Review Technique (PERT) and Critical Path Method (CPM), which were also the first methods developed. Initially, PERT was built to prepare and control the Polaris rocket, an extensive project involving thousands of operations, using more than 3,000 contractors. As a result, the project’s duration was reduced by two years. Many government contracts also involve the use of PERT or a similar technique because of its effectiveness. CPM was designed initially for the preparation and coordination of chemical plant maintenance programs ^[4].

Description of Network Planning in Project Management

From the complexity perspective, the central part of ISO 21500 discusses project and project management. It suggests structural, technical expertise to be implemented in a particular sequence in the form of activities. Thus, projects operate smoothly, effectively, and efficiently. Moreover, activities related to complexity are linked to the planning processes and involve the functions necessary to manage and control various project-related activities. The primary purpose of network planning in project management is to aid in the planning, managing, and controlling of projects ^[1].

Network planning is a sequential categorization of the activities involved in the project's execution, accompanied by a graphical presentation of the actions required for the project as a whole. Therefore, network planning is a distributed model of work to be done in a project. A hierarchy of interdependent job elements, which are processes, tasks, and activities, is sequenced and prioritized to identify and describe the overall project effort. Typically, the project network is constructed and built using charts and hierarchical diagrams or often termed project network diagrams ^[5].

Multiple sequences of activities are included in the network planning that specifies one or another aspect of work, for example, a process or phase. The main criterion for the network planning efficiency is that each sequence of activities should have a finite and measurable outcome and never contain circular references. If there is a circular reference in an operation chain, it creates a closed-loop, resulting in an endless cycle ^[5].

Application

Network Planning Tools

As mentioned before, the most common network planning tools are the CPM and PERT, and they both have similar characteristics. The first characteristic is that it is possible to break the project down into a well-defined set of activities or jobs. It is essential to perform these activities in a specific sequence. Lastly, the operation should be started and stopped within a given sequence.

However, the main difference between these network planning tools is that CPM is determinist structured and PERT probabilistic. Therefore, for traditional, routine projects with a comprehensively known and well-defined scope, and the possible changes and risks merely marginally affect the entire course of the project, CPM is recommended. Additionally, for the purpose of measuring a project with a technique like CPM, its length should be viewed as a single value for each activity, such as five working days. Conversely, reality often changes and is unpredictable, and therefore executing reasonable quality estimates is difficult and costly. Hence, a probabilistic approach and the use of PERT are suggested to represent better the effect of risk and uncertainty on a project and improve the reliability of the forecasts ^[6].

The article, Comparison between Deterministic and Stochastic Time Estimating Techniques, explains the difference between deterministic and stochastic approaches. There it is mentioned that two-time dimensions influence time management, which is the actual time and calendar time. Furthermore, while there are numerous existing estimating techniques, the deterministic and stochastic are the most commonly used in the time estimation process. Historically, most project management practitioners use one or the other as their essential technique for estimating time. This article examines these two techniques and determines, like others have, that no specific method is more suitable in each estimating situation. As verified by others, it was recommended that CPM be used when activity times are predictable (deterministic) ^[7].

In contrast, PERT techniques should be used in cases where activity times are unpredictable (probabilistic). PERT gives a more reliable estimate for projects that allow for a more extended period of time for completion and difficult to estimate. On the other hand, CPM is a good alternative for traditional projects with predictable tasks and assignments. It is therefore inferred, on the whole, that PERT offers a better model for estimating than CPM ^[7].

Limitations

Annotated Bibliography

Kosztyán Z.T., Kiss J. (2010) Stochastic Network Planning Method. In: Elleithy K. (eds) Advanced Techniques in Computing Sciences and Software Engineering. Springer, Dordrecht. https://doi.org/10.1007/978-90-481-3660-5_44: This article describes the Stochastic Network Planning Method (SNPM) and references several studies where projects fail due to uncertainty and inaccurate estimates. Moreover, this article explains the advantages of SNPM over some of the most known methods of network planning, PERT and GERT. The benefit of SNPM is that it finds potential solutions with the aid of stochastic variables and that all possible successor relations are taken into account. In this process, if the effect on the project changes, the parameters can be modified due to changes in the market's technological conditions or tendencies. The SNPM may thus be useful as an expert system module.

Briggs D. G. (2017) Comparison between Deterministic and Stochastic Time Estimating Techniques. In: International Journal of Advanced Research in Science, Engineering and Technology. IJARSET. http://www.ijarset.com/upload/2017/july/21-IJARSET-daketima.pdf: This paper identifies the difference between the two main techniques of network planning, CPM and PERT. Time is one of the variables in project management that provides inputs for use in project scheduling. There are two dimensions of time that impact time management: real-time and calendar time. There are a variety of estimation techniques available. Two methods are most widely used in the time estimation process among the different methods: the determinist (single-point) estimation technique and stochastic (three-point) estimation technique. This article argues that in situations where activity times are predictable (deterministic), CPM should be used, while PERT techniques should be used in cases where activity times are unpredictable (probabilistic). Furthermore, it concludes that PERT offers a better model for estimating than CPM.

Taylor, B. W. (1978). Project management using GERT analysis. Project Management Quarterly, 9(3), 15–20.: This article explains the modeling technique and simulation package of the GERT network and demonstrates its capabilities by planning for R&D projects. Additionally, a summary of the use of GERT performance for management planning and control, including sensitivity analysis and implementation, is included.

References

1. ↑ ^{1.0 1.1} J. Geraldi, C. Thuesen, & J. Oehmen. (2017). Doing Projects - Nordic flavour to managing projects. Danish Standards Foundation.
2. ↑ ^{2.0 2.1} Rand G.K., Tavares L.V. (2001) Network planning. In: Gass S.I., Harris C.M. (eds) Encyclopedia of Operations Research and Management Science. Springer, New York, NY. https://doi.org/10.1007/1-4020-0611-X_665
3. ↑ Project Management Institute. (2010). A Guide to the Project Management Body of Knowledge (PMBOK Guide). Project Management Institute. ISBN: 9781930699458, 193069945X
4. ↑ R. Dan Reid & Nada R. Sanders. (2013). Operations Management: An Integrated Approach, 5th Edition International Student Version. Wiley. ISBN: 978-1-118-55566-8
5. ↑ ^{5.0 5.1} A. Shaddra. (n.d.). Project Scheduling and Network Planning (With Diagram). https://www.yourarticlelibrary.com/project-management/project-scheduling-and-network-planning-with-diagram/95024/. Visited: 15.02.2021
6. ↑ Wyrozębski, Paweł & Wyrozębska, Agnieszka. (2013). Challenges of project planning in the probabilistic approach using PERT, GERT and Monte Carlo. Journal of Management and Marketing. 1. 1-8.
7. ↑ ^{7.0 7.1} Briggs D. G. (2017). Comparison between Deterministic and Stochastic Time Estimating Techniques. In: International Journal of Advanced Research in Science, Engineering and Technology. IJARSET. http://www.ijarset.com/upload/2017/july/21-IJARSET-daketima.pdf