Standard Guide for Schedule Performance Index, Schedule Beta (βs)

Importancia y uso:

5.1 The schedule beta (β_s) approach produces informational elements: Overall (or composite) schedule beta (β_s), schedule beta upside (β_s+), and schedule beta downside (β_s–)—representing the quantitative components, and the qualitative insight (“early warning”) into the propensity for directional schedule performance for individual schedule participants.

5.1.1 The quantitative component of schedule beta (β_s) (inclusive of the upside and downside subvariants) is an index value that depicts schedule participant’s magnitude and direction of movement as compared to the overall project at an assigned value of 1.0, for example, a β_s = +2.5 connotes performance of a schedule participant that moves in the same direction as the collection of completed projects at a rate of 2.5 units (schedule days) for each single unit (schedule day) experienced at the overall project level.

5.1.2 The qualitative component of schedule beta (β_s) (inclusive of the upside and downside subvariants) provides insight as a cautionary and predictive signal depicting the ability for an individual schedule participant to perform in-keeping with the initially-established as-planned schedule duration(s).

5.2 Schedule beta (β_s) also depicts the overall status or health (performing well or not) of a market sector, location and/or trade. Consistent larger schedule beta (β_s) values are indicative of external elements (risks) impacting all participants sharing common attribute(s) (that is, trade, location, market sector, etc.).

5.3 Schedule beta (β_s) measures current schedule participant performance. As a rolling value (for example, calculated for projects completed during the two most recently completed full calendar years), it depicts the schedule performance ability of the schedule participant. See Note 1.

Note 1: Schedule Data Source and Usage—Schedule beta (β_s) (inclusive of the upside and downside subvariants) utilizes schedule data from any schedule calculation method that depicts individual activity duration versus overall project duration and is updated on a regular basis. Data are used for calculation, comparison, and/or contrasting purposes. They are not created under this guide. Schedule beta (β_s) uses four data points from the external scheduling method: as-planned and as-built durations for both individual activity and the overall construction project in its calculation – see Section 3 for definitions.

5.3.1 Improving Values—Schedule beta (β_s), schedule beta upside (β_s+), and schedule beta downside (β_s–) are characterized as improving when their value decreases in magnitude (that is, β_s = +2.5 becomes β_s = +1.75 and β_s = –1.25 becomes β_s = –3.0).

5.3.2 Deteriorating Values—Schedule beta (β_s), schedule beta upside (β_s+), and schedule beta downside (β_s–) are characterized as deteriorating when their value increases in magnitude (that is, β_s = +0.5 becomes β_s = +1. 5 and β_s = –2.25 becomes β_s = –1.0).

5.4 Schedule beta (β_s) (inclusive of the upside and downside subvariants) is capable of being calculated any time a project reaches completion and no further activity (no additional days) are recorded within an overall project schedule.

5.4.1 Any schedule participant having completed their work in at least two (2) distinct (mutually exclusive) completed projects may calculate the full array of schedule beta values—schedule beta (β_s), schedule beta upside (β_s+), and schedule beta downside (β_s–).

Subcomité:

E06.81

Volúmen:

04.12

Número ICS:

03.060 (Finances. Banking. Monetary systems. Insurance)

Palabras clave:

activity; actual duration; as-planned duration; beta; capital asset pricing model; CAPM; CPM; critical path method; duration; performance measure; planned duration; project; schedule; schedule beta; schedule performance;