Cálculo de los costos indirectos de fabricación

As discussed in the last section, traditional performance measurement techniques were used to analyse the entire sequence. A series of two-

dimensional s-curves were produced (see Chapter 4). BAG (Budget At Completion), EAC (Estimate At Completion) and ETC (Estimate To

Complete) were plotted against each other up to milestone 7, as a cost/time s-curve. It should be noted that the chosen s-curves have a 3D appearance. In fact, this is a 3D view of a 2D chart. It was chosen because it aided the intelligibility of the s-curve. Although the s-curves appear 3D, they are really 2D plot lines stacked on top of each other. The number of dimensions is still 2 (time x performance/cost) as opposed to Procession's 3 (deviation

parameter x task x deviation level).

The expected total cost of the project (before it started) was

£6,247,849. By the end of the planned project time-scale for scenario one, £6,169,170.78 had been spent and in order to complete (behind schedule), an additional £14,533,790.31 was required. The total project cost would then have spiralled to £20,781,638.82 (see Figure 8.5). In scenario 2, 100% of the £6,247,849 predicted costs had been spent by the end of the planned project time-scale and in order to complete (behind schedule), an additional

£56,751,522.90 was required. The total project cost would then have spiralled to £62,920,693.68 (see Figure 8.6).

CPI (Cost Performance Analysis) was plotted against SPI (Schedule Performance Analysis) as an s-curve to identify trends within the project progress. In Completion Cost Analysis (Section 4.4), a flat line indicates that the baseline is being achieved on a £ for £ basis. Values below £1, suggest that the project is either over-budget or behind schedule.

For scenario 1, the CPI and SPI showed that both the schedule and the budget trends were deteriorating rapidly before the first milestone. In the second quarter, both budget and schedule stabilised. By the third milestone.

a slight improvement was seen in both curves, however they quickly dipped back and continued at approximately £0.30 for the rest of the schedule. At completion, the project was both behind schedule and over budget (see Figure 8.7).

Scenario 2 saw both the schedule and the budget plans deteriorating rapidly before the first milestone. In the second quarter, the budget stabilised, while the schedule continued to slip. By the third milestone, the schedule was stabilising and it continued to mirror the budget curve, with a differential of approximately £0.20. This continued until the scheduled completion date, with only a slight budget recovery in the last quarter. At completion, the project was still very behind schedule and over budget. The final CPI value reveals that £0.10 of value was being earned for every £1 spent (see Figure 8.8).

BOWS (Budgeted Cost of Work Scheduled) was plotted against BCWP (Budgeted Cost of Work Performed) and ACWP (Actual Cost of Work Performed) to produce an s-curve of Earned Value (see Section 4.3). For scenario 1, expenditure stayed almost as expected (ACWP and BCWS tracked each other throughout) but earned value (BCWP) slowly deteriorated throughout the sequence. Therefore, the work completed by the planned completion date had cost far more than budgeted and the schedule had proven to be over optimistic (see Figure 8.9). Throughout scenario 2, ACWP almost followed the budget in the baseline schedule, but increased in task durations. This resulted in the scheduled expenditure (BCWS) levelling out to match a longer time-scale. Despite slow improvement through the sequence, the earned value (BCWP) was so low compared with the ACWP, that the situation became irretrievable (see Figure 8.10). As previously stated, RSL Informants were asked to assess project performance at Milestone 4, using Earned Value Analysis. Status codes have been given to the project at Milestone 4, to enable questionnaire scoring.

At Milestone 4 scenario 1 was:

On budget behind schedule- schedule performance deteriorating and cost performance stabilised with a status code of 4.6 (see last pages of Appendix 6, Initial Prototype Usability and Information Evaluation Protocol).

The sequence outcome for scenario 1 was:

Project had run out of time and budget to complete. No cost overruns had been incurred to date but more funds would be required to continue.

At Milestone 4 scenario 2 was:

Over budget behind schedule- schedule performance deteriorating and cost performance deteriorating with a status code of 7.5 (see last pages of

Appendix 6, Initial Prototype Usability and Information Evaluation Protocol).

The sequence outcome for scenario 2 was:

Project had run out of time and budget to complete. No cost overruns had been incurred to date but funds totalling many times the original budget would be required to continue.

Finally, two sets of seven milestone Microsoft Project files were generated, one for each scenario. To simulate progress at each milestone, changes were made to the tasks, in terms of their durations and percentages complete. For each scenario, it was necessary to work through the milestone files chronologically. This is because Microsoft Project always passes revised estimates onto the next milestone in the sequence. CSV data files for

Procession were exported from each of the Microsoft Project milestone files (i.e. 14 files total).

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8.8 Comparative milestones as shown to RSL Informants: s-curves vs. data