Cost control with statistic tools

Introduction

Cost control is one of the major parts in the cost management in Project management. Cost control is the process of monitoring project status to update project costs and managing changes to the cost baseline. The main benefit of this process is that the cost baseline is maintained throughout the project. The appropriateness of this process is that the cost baseline is maintained throughout the project.

Under the conditions of a market economy, the pursuit of profit maximization and improving economic efficiency are the main goals of enterprises. Controlling project costs is an important way for companies to reduce costs and increase profits. Controlling project costs is an important guarantee for enhancing the competitiveness of enterprises. Therefore, it is necessary to strengthen project cost management, continuously reduce costs, improve enterprise competitiveness, and increase economic benefits.

The major component of the Project cost control includes:

• Influencing the factors that create changes to the authorized cost baseline;
• Ensuring that all change requests are acted on in a timely manner;
• Managing the actual changes when and as they occur;
• Ensuring that cost expenditures do not exceed the authorized funding by period, by WBS component, by activity, and in total for the project;
• Monitoring cost performance to isolate and understand variances from the approved cost baseline;
• Monitoring work performance against funds expended;
• Preventing unapproved changes from being included in the reported cost or resource usage;
• Informing appropriate stakeholders of all approved changes and associated cost; and
• Bringing expected cost overruns within acceptable limits.

Cost Control Input

The input of the cost control includes following parts:

• Project management plan, which includes cost management plan, cost baseline and performance measurement baseline. The cost management plan indicates how the project cost will be managed and controlled. The cost baseline is applied as the comparison with actual results to determine if a change, corrective action, or preventive action is necessary. Similarly, performance measurement baseline is compared to actual results to determine if a change, corrective action, or preventive action is necessary.
• Project documents: Lessons learned earlier in the project can be applied to later phases in the project to improve cost control.
• Project funding requirements: The project funding requirements include projected expenditures and anticipated liabilities.
• Work performance data: Work performance data contains data on project status such as which costs have been authorized, incurred, invoiced, and paid
• Organizational process assets: The organizational process assets that can influence the Control Costs process include: Existing formal and informal cost control-related policies, procedures, and guidelines; Cost control tools; and Monitoring and reporting methods to be used.

Earned Value Method

Earned value analysis compares the performance measurement baseline to the actual schedule and cost performance. EVM integrates the scope baseline with the cost baseline and schedule baseline to form the performance measurement baseline. EVM develops and monitors three key dimensions for each work package and control account:

• Planned value. Planned value (PV) is the authorized budget assigned to scheduled work. It is the authorized budget planned for the work to be accomplished for an activity or work breakdown structure (WBS) component, not including management reserve. This budget is allocated by phase over the life of the project, but at a given point in time, planned value defines the physical work that should have been accomplished. The total of the fines the physical work that should have been accomplished. The total of the PV is sometimes referred to as the performance measurement baseline (PMB). The total planned value for the project is also known as budget at completion (BAC).
• Earned value. Earned value (EV) is a measure of work performed expressed in terms of the budget authorized for that work. It is the budget associated with the authorized work that has been completed. The EV being measured needs to be related to the PMB, and the EV measured cannot be greater than the authorized PV budget for a component. The EV is often used to calculate the percent complete of a project. Progress measurement criteria should be established for each WBS component to measure work in progress. Project managers monitor EV, both incrementally to determine current status and cumulatively to determine the long-

term performance trends.

• Actual cost. Actual cost (AC) is the realized cost incurred for the work performed on an activity during a specific time period. It is the total cost incurred in accomplishing the work that the EV measured. The AC needs to correspond in definition to what was budgeted in the PV and measured in the EV (e.g., direct hours only, direct costs only, or all costs including indirect costs). The AC will have no upper limit; whatever is spent to achieve the EV will be measured.

References

• Project Management: A guide to the Project Management Body of Knowledge (PMBOK guide) 6th Edition (2017)
• Project Management Institute(PMI). (2005) "Practice Standard for Earned Value Management"
• Aliverdi, R., Moslemi Naeni, L., & Salehipour, A. (2013). Monitoring project duration and cost in a construction project by applying statistical quality control charts. International Journal of Project Management, 31(3), 411–423. https://doi.org/10.1016/j.ijproman.2012.08.005
• Hadian, H., & Rahimifard, A. (2019). Multivariate statistical control chart and process capability indices for simultaneous monitoring of project duration and cost. Computers and Industrial Engineering, 130(March), 788–797. https://doi.org/10.1016/j.cie.2019.03.021