Managing Project Time

Project managers know that the iron triangle of project management are constrained by three elements – time, cost and scope. Each project is given a set timeframe for the project deliverables or goals to be achieved and many struggle to meet this timeframe.

Estimation techniques

Expert judgment is often used to assess task durations and efforts. Expert judgment is gained often through experience allowing comparison to previously completed work in order to allow a prediction of future work. An example of this would be in estimating duration for a task such as laying bricks. An expert in the field would be able to assess the duration of such a task by utilizing a rule of thumb quantity per day per bricklayer. Assessing how many bricklayers would be expected to be operating in the space available and therefore be able to ascertain a time length and effort involved in the task. Expert judgment may also extend to specialists in the field, consultants and sub-contractors are often consulted to determine task durations and efforts in-fact many sub-contractors or specialist consultants may drive task and/or project duration. It is important during the use of expert judgment that schedules are produced that are neither too conservative or optimistic and that they can constantly change as required when new information is presented. View course details for the Diploma of Project Management.

Published estimating data is also frequently used. Books such as Rawlingsons are published and sold to construction companies the world over. These books go into quite a significant amount of detail in how they should be used and read. They have a very large range of material and labour quantities and costs through many facets of construction. Often the data can be used independently or with alterations. For instance, data may publish a rate which you may discover is old or outdated, particularly with items that are subject to large price increases. Therefore, the costs may be able to be adjusted, or the labour component used to determine time and the material costs discovered from another source. Publications such as these can be very helpful but certainly cannot be used in isolation as there are dangers in relying solely on works such as these. There is always a gap between existing and new construction techniques as often newer construction techniques do not make their way into these publications until they have proven themselves in the market.

How do you identify a project’s critical path?

The critical path is determined by following the path generated by the longest durations. It is the sequence of all activities that must be completed for the entire project to be completed. If there are multiple tasks occurring at one time, the task that will form the critical path will be the task with the longest duration. For this to be successful all tasks must have at least one predecessor and one successor except for the first and last tasks. If a task is deemed to on the critical path and it is delayed by one day, then the project will have delayed by one day.

Critical paths have either zero or negative float, if a task can be delayed without an impact on the project than it will not be on the critical path. Units covered by Diploma of Project management. 

A manual way of determining the critical path is via the use of a schedule network diagram. Once this is plotted you can determine all possible paths available and calculate the duration for each individual path. If the schedule has been plotted on a software system such as Microsoft Project, the critical path can be determined by the software. It is important however, for this to be reviewed and sometimes adjustment may need to be made, as the programmed critical path line may not go where you would like. Adjustments would be made to other tasks in this case to reduce float.

How to manage project baselines, establishment and variance

Once a schedule has been fully developed, a schedule baseline is created and accepted by the project managing team. This schedule provides the project start and finish dates, identifies the critical path and provides a fixed point on which the project performance can be measured against. The critical path established may change throughout the project due to tasks completing early or running late. Often multiple baselines can be created dependant on the scope of the works or unknown or latent conditions which could drastically alter the original schedule baseline where it becomes unpractical to measure changes. Schedule control is required to ensure that the project schedule is updated when events require it. Often such a review period would occur at major milestones, change of personnel that impact the program such as key staff, completion of deliverables and finalisation of the project. The project manager works with the stakeholders and clients to ensure that changes are agreed upon, the project manager examines the results and conditions on site to determine if such changes have occurred. The project manager will also implement these changes into the program.

A schedule control system could be used for managing the mentioned changes and facilitates the tracking of changes, approval processes and does this considering the conditions of the change requests, reasons, costs and risks of these changes. Alterations to the schedule can also be driven by poor performance, this is needed to be monitored using performance review which considers actual start and finish dates, percentage complete and remaining durations. Part of the project management process is identifying when corrective action could be required dependant on the overall impact of poor performance on an activity. Performance of this analysis is key in controlling the schedule, the comparisons can be often viewed in a comparison bar chart where the baseline and the schedule changes can be reviewed side by side and slippage can be visually identified. At these points the schedule can be reviewed for potential forecasting changes that could be implemented into bringing the schedule back towards the baseline. What if scenarios, resource levelling and adjusting leads and lags can be used to identify the changes that would be required to reduce delay to the project.

Schedule variance and schedule performance index values for the WBS components are documented and presented to stakeholders, schedule variance analysis and progress reports may have impacts to other components of the project management plan. Learn how to mangage project budget by clicking here.

The importance of discovering the root problem of the delay or schedule variance cannot be overlooked. This can often be tracked using document and records such as site diaries, incident records and occurrence reports, scheduling charts, evaluation of options, variances, records of analysis and review of work breakdown structure. A big part of managing a project is ensuring you will learn how to manager cash flow.