A simple interactive example of a progress report based on the Earned Value method (part 1)

Keeping track of project performance based on the Earned Value method

The following is a simple interactive example of a progress graphic report based on the Earned Value method. This method uses an extra variable that represents the actual cost of the work done at a given point. This data is compared with the earned value to measure the performance of a project in terms of cost and schedule, with respect to the contract, baseline or initial agreement of the work to be done. So, it's possible, at any given point, to compare how much actual work has been completed against how much is expected to be completed. 

For information on this topic see Earned Value Management and my previous posts A Simple Method for Keeping Track of Project Performance using the Earned Value Method and Multiple Projects Performance Analysis using the Earned Value Method.  More information can be found in any project management related material.

The example consists of undertaking and completing 10 "equal" components in 10 working days with a budgeted cost of  $10,000.00, based on a fixed price contract. Hence, the project has the following initial agreements:
  • estimated time duration = 10 days
  • estimated budget = $ 10,000 
  • equal components means that all components take an equal amount of time and money to build
To see how the project is performing, use the form below to input the elapsed time to date, number of components produced to date the actual cost (n.b., data is bounded by initial agreement ). So, it's possible, at any given point, to compare how much actual work has been completed against how much is expected to be completed. Moreover, the variance calculations shows the situation of the project, that is, if the project is running ahead or behind schedule and if it's under or over budget.

Input Data

Output Data Graph
This is a simple output graph illustrating cost and schedule variance against time. This chart can be customized and enriched with more details to suit specific purposes and further analyze each single case at a given point of time.
(CV = Cost Variance: a positive value means the project is running under budget, a negative value means over budget (spending more than what is planned for) and a zero means the situation is on track.
SV = Schedule Variance: a positive value means the project is running ahead of schedule (producing more than what is expected), a negative value means behind schedule and a zero means the situation is on track.)

(refresh rate every 10 seconds)

Another example of a responsive output graph linked to the above Input Data form is the  cost and schedule performance index.
  • CPI (Cost Performance Index): greater than 1 means under budget; less than 1 means over budget.
  • SPI (Schedule Performance Index): greater than 1 means ahead schedule; less than 1 means behind schedule.
In general, ideally, performance index greater than 1 means good and less than 1 means bad. But, each single case must be analyzed to get a better understanding of the situation at a given point in the project timeline, because greater than 1 might not necessarily mean good.

In this example, there is no relationship between the predecessor and successor instance within the graph, hence, each case is to be treated as a singular case. But, in a real project network diagram where all relationships between tasks have been set to place, snapshots of various patterns can be created. This will give the opportunity to recognize, at a glance, each single case, i.e., the state of the project's situation at a given point (within that part of the project timeline that has been achieved).

(Please read the "N.B." note inside the above Input Data form)

(refresh rate every 10 seconds)

Interactive example using PERT estimating technique

Regardless of the technique you use for estimating tasks, each estimate has to be quantified into a number. There are different ways for estimating project tasks, for example: 
  • Use of Historical Data - "similar" projects categorized in a knowledge database system can be retrieved and consulted when making estimates.
  • Use of Experienced Resources - estimating is a team effort, and the contribution from experienced resources in making estimation is very valuable.
  • Use of Estimating Databases - make use of industry databases made available by organizations.
In many cases estimates can be made more accurate by applying a simple PERT (Program Evaluation and Review Technique) model. PERT is an estimating technique that uses a weighted average of three numbers to come up with a final estimate.
The PERT distribution comes out of the need to describe the uncertainty in tasks during the development of a complex project having thousands of tasks. Estimates were needed to be made intuitively, quick and consistent in approach. The PERT distribution is a probabilistic model based on Beta Distribution, and it derives its estimates based on the probability of occurrence. A version of this four-parameter Beta distribution is called a PERT distribution and makes the assumption that the MEAN = (MINIMUM + 4*MOST LIKELY + MAXIMUM) / 6. The default value of 4 scales the height of the distribution. This extra equation allows the four parameters to be determined from three input values: the minimum, most likely and maximum, which makes it ideal for modeling expert opinion of  the uncertainty of a variable.
  • E = Expected Value = (O+4M+P)/6 (this is the "weighted" average equation
  • P: Pessimistic value (this value is maximum, because it describes the case when things go wrong)
  • O: Optimistic value (this value is minimum, because it describes the case where things go right)
  • M: Most Likely value (this value describes the case given normal problems and opportunities)
For example, let's suppose we want a more accurate estimate of a task duration that is collocated in a Project Network Diagram, given the following values:
  • P = 20 programmer days  (pessimistic value when everything goes wrong)
  • M = 15 programmer days (most likely) 
  • O = 10 programmer days (optimistic value where everything goes right)
Use the following interactive form to get the expected task duration (mean value) for the above example.
(Similar tasks can be categorized to create a histogram and it's possible to use the last chart below to highlight the mean value graphically, as stepped area across all other values).

Input Data (M,O,P)

Output Data Table (PERT Estimate)
(refresh rate every 10 seconds)

Output Data Graphically (PERT Estimate)
(refresh rate every 10 seconds)