Công cụ quản lý dự án Leads & Lags trong PMP là gì?
A lead is the amount of time whereby a successor activity can be advanced with respect to a predecessor activity. For example, on a project to construct a new office building, the landscaping could be scheduled to start two weeks prior to the scheduled punch list completion. This would be shown as a finish-to-start with a two-week lead. Lead is often represented as a negative value for lag in scheduling software.
A lag is the amount of time whereby a successor activity will be delayed with respect to a predecessor activity. For example, a technical writing team may begin editing the draft of a large document 15 days after they begin writing it. This can be shown as a start-to-start relationship with a 15-day lag as shown in above figure. Lag can also be represented in project schedule network diagrams as shown in below Figure in the relationship between activities H and I, as indicated by the nomenclature SS+10 (start-to-start plus 10 days lag) even though offset is not shown relative to a timescale.
The project management team determines the dependencies that may require a lead or a lag to accurately define the logical relationship. The use of leads and lags should not replace schedule logic. Activities and their related assumptions should be documented.