TimeCentric Earned Value
What we have discussed to this point is the traditional and most robust form of earned value. Whenever the resources are available to apply the method, it should be done because it focuses on the accomplishments that lead to project value being delivered as promised. However, the collection and reporting of actual cost is often impractical, thereby rendering the quantitative measures unobtainable. In that event, there is an alternative, though less robust, earned value method named "timecentric earned value," ^{[12]} first described to the industry in the author's presentation ^{[13]} with James R. Sumara to the PMIŽ National Symposium in 1997.
TimeCentric Principles
The main idea behind the timecentric earned value system is to set a PMB based on planned work package starts and finishes over the course of the project. Timecentric earned value is very close to the concept of "work units" or "standard units of work" as a measure of accomplishment rather than a specific dollarized WBS cost account. Instead of a standard unit of work, however, timecentric earned value focuses on a completed task, with unknown actual cost, as the unit of value in the project.
Although a dollar value is not assigned to each work package start or finish, the total collection of starts and finishes, if executed completely, does represent the total scope (and value) of the project. The total scope of the project does have a dollar planned value (budget).
The historical reporting for purposes of determining variances remains a component of the timecentric system. Instead of earning a dollar value, what is earned is a start or a finish. The PMB is a set of planned starts and planned finishes. Therefore, there is a variance that can be defined thus:
Variance (start) 
= 
Earned starts  Planned starts 
Variance (finish) 
= 
Earned finishes  Planned finishes 
All the rules we have discussed about what constitutes a claim of credit apply. The definitions of start and finish used in the traditional method to gate the expenses for purposes of calculating the variances to the earned and planned value still apply, but apply to whether a task start can be claimed and not whether actual cost is to be applied. So too do the ideas of rebaselining, calculating the ETC, and the EAC still apply, but apply to the idea of finishing the project on a time basis and not a cost basis.
Timecentric indexes can also be defined and calculated:
Task start performance index (TSPI) 
= 
(Earned starts)/(Planned starts) 
Task finish performance index (TFPI) 
= 
(Earned finishes)/(Planned finishes) 
Figure 65 provides an illustration of a project wherein the PMB has 20 starts in the first three periods. We see in this figure that the project team has indeed started 20 tasks, but the starts are at a different pace than planned. We can calculate a variance for each period:
Start variance_{1} 
= 
3  5 = 2 starts 
Start variance_{2} 
= 
9  10 = 1 start 
Start variance_{3} 
= 
6  5 = 1 start 
Start variance_{4} 
= 
2  0 = 2 starts 
Σ (All variances) 
= 
0 start 
Figure 65: TimeCentric Project Start Example.
At the end of four periods, the project is caught up on starts. The project manager can also forecast how soon the project will attain all the starts planned in the PMB using the performance indexes. Table 66 provides the start performance metrics. Similarly, we see in Figure 66 the finish performance for the example project. Variances similar to the start variances can be calculated; indexes can also be calculated as was done for the project starts. Table 67 provides those calculations.
Planned Starts by Month ^{[*]} 
Actual Starts by Month 
Monthly Index 
Cumulative Index 
Forecasted Finish 

Month 1: 5 starts 
Month 1: 3 starts 
TSPI_{1} = 3/5 = 0.6 
Cum Starts = 3 Remaining = 17 Cum = 3/5 = 0.6 
Adjusted remaining starts = 17/0.6 = 28 Forecast schedule remaining = 2 months * 28/17 = 3.3 months 
Month 2: 10 starts 
Month 2: 9 starts 
TSPI_{2} = 9/10 = 0.9 
Cum Starts = 12 Remaining = 8 Cum = 12/15 = 0.8 
Adjusted remaining starts = 8/0.8 = 10 Forecast schedule remaining = 1 month * 10/8 = 1.25 months 
Month 3: 5 starts 
Month 3: 6 starts 
TSPI_{3} = 6/5 = 1.2 
Cum Starts = 18 Remaining = 2 Cum = 18/20 = 0.9 
Adjusted remaining starts = 2/0.9 = 2.2 Forecast schedule remaining = 0 months * 2.2/2 = 0 months (no remaining schedule available) 
Month 4: 0 starts 
Month 4: 2 starts 
TSPI_{4} = 2/0 = indefinite 
Cum Starts = 20 Remaining = 0 Cum = 20/20 = 1.0 
Adjusted remaining starts = 0/1 = 0 Forecast schedule remaining = 0/0 = indefinite 
^{[*]}See related figure for a graphical presentation of this example. 
Planned Finishes by Month ^{[*]} 
Actual Finishes by Month 
Monthly Index 
Cumulative Index 
Forecasted Finish 

Month 4: 3 finishes 
Month 1: 3 finishes 
TFPI_{1} = 3/3 = 1 
Cum Finishes = 3 Remaining = 17 Cum = 3/3 = 1.0 
Adjusted remaining finishes = 17/1 = 17 Forecast schedule remaining = 2 months * 17/17 = 2 months 
Month 5: 10 finishes 
Month 2: 7 finishes 
TFPI_{2} = 7/10 = 0.7 
Cum Finishes = 10 Remaining = 10 Cum = 10/13 = 0.77 
Adjusted remaining finishes = 10/0.77 = 10.4 Forecast schedule remaining = 1 month * 10.4/10 = 1.04 months 
Month 6: 7 finishes 
Month 3: 6 finishes 
TFPI_{3} = 6/7 = 0.86 
Cum Finishes = 16 Remaining = 4 Cum = 16/20 = 0.8 
Adjusted remaining finishes = 4/0.8 = 5 Forecast schedule remaining = 0 months * 5/4 = 0 months (no remaining schedule available) 
Month 7: 0 finishes 
Month 4: 4 finishes 
TFPI_{4} = 4/0 = indefinite 
Cum Finishes = 20 Remaining = 0 Cum = 20/20 = 1.0 
Adjusted remaining finishes = 0/1 = 0 Forecast schedule remaining = 0/0 = indefinite 
^{[*]}See related figure for a graphical presentation of this example. 
Figure 66: TimeCentric Project Finish Example.
Forecasting with the TimeCentric System
Just like in the traditional earned value system, forecasts can be made using the same formula as we developed for the forecast in that system:

Forecast = Actual performance + Remaining performance/Index
For example, in the first period the actual starts are 3, the remaining performance for the project is 17, and the index is 0.6. The forecast is therefore:
First period index 
= 
3/5 = 0.6 
Actual starts 
= 
3 
Forecast 
= 
3 + 17/0.6 = 3 + 28.3 = 31.3 starts 
where 31.3 = "equivalent" starts.
How should the project manager interpret the forecast given above? The equivalent starts represent the length of the project as though the PMB were 31.3 starts rather than 20. In other words, based on the performance in the first period, the project is forecasted to be 11.3/20 = 56.5% longer in schedule than the PMB. Fortunately, by the second period the trend line turns more favorable:
Cumulative index 
= 
12/15 = 0.8 
Cumulative starts 
= 
12 
Forecast 
= 
12 + 8/0.8 = 22 starts 
where 22 = "equivalent" starts.
As with the traditional earned value system, the most valuable contribution of the calculations is to stimulate the project team to take action necessary to deliver the value to the project sponsor as defined on the project balance sheet and specified in the project charter. Whether or not the timecentric or traditional system is used, the calculations should have the same effect and provide the requisite catalyst to correct whatever is not working well in the project.
^{[12]}The original work on "timecentric earned value" was done by the author and colleague James Sumara while working with the Lanier Worldwide business unit of Harris Corporation in the mid1990s. Although the traditional earned value system was well known and practiced at Harris, the Lanier Worldwide business unit did not have the mechanisms for complete collection of the actual cost of the labor employed for internal projects. Timecentric earned value was developed for the Lanier Worldwide project office to fill the need for an earned value reporting tool.
^{[13]}Goodpasture, John C. and Sumara, James R., Earned Value — The Next Generation — A Practical Application for Commercial Projects, PMI '97 Seminars and Symposium Proceedings, Project Management Institute, Newtown Square, PA, 1997.