Lead time critical path

The standard requires that measurements be defined, analyzed, and reported to management at appropriate stages of product realization and that these measurements include quality risk, costs, lead times, critical paths, and others as appropriate. 

The extent to which planned tasks are being completed on time The degree of slippage or slack in the program The critical paths and changes in criticality Lead times and effect of changes on advanced procurement Resource utilization Spend versus budget Estimated spend to completion... 

For scheduling, a closed sequence pltui is assumed to exist. The activities and correlations must be determined beforehand. Therefore, the minimum task of the scheduling part of the process is the calculation and determination of time limits, criticed paths, and buffer times. The CPM, MPM, and PERT methods are implemented for this purpose, and the incorporation of these operations leads to the calculation of complete process and buffer times using both forward and backward calculations. 

Moving from long to short lead-times - Overall lead-time is composed of individual cycle-times for multiple processes. This step involves shortening the cycle-time at each step in the critical path processes from the point of purchase to the start of production for the entire supply chain. 

For each operation in the supply chain, the map depicts lead-time. The heavy line shows the critical path. For Process, for example. Figure 28.7 and Table 28.4 show that material for Process is on the critical path and has a five-day lead-time. Internal operations at Process require another 30 days. So, the total lead-time at Process is 35 days. Likewise, Old Line requires 95 days of lead-time, with 35 accounted for by material from Process and 60 by internal processes. Material for Process is not on the critical path so the 35 days does not count toward lead-time. Notice one supply chain step (No. 7) at Process takes 45 days, which could indicate a supply chain bottleneck. 

External sources for Old Line and High Tech are not displayed, as they are not on the critical path. The resulting map shows a lengthy, but not untypical, supply chain lead-time of 195 days. About half is internal to High Tech, the end producer. The other half is upstream of High Tech. A major delay is encountered at a bottleneck in Old Line s processes that requires 45 days. 

Lead-times like these necessitate forecasting and have spurred the search for methods to attack them. The map helps to focus efforts to shorten the supply chain lead-time where they will be the most effective. For example, there appears to be little benefit, at least initially, from an effort to shorten lead-times among High suppliers. They are not on the critical path. A better choice is supplier lead-time for Process, although it is relatively short, or attacking the bottleneck at Old Line. 

One of the most interesting results of [41 ] is the relatively poor performance of TWKCP, which follows the traditional approach of setting lead times based on the critical path in the BOM. The best performers were those rules which considered both the critical path and the system congestion in a i additive rather than a multiplicative form. 

The initiatives and processes in lean project management are deriving benefits from two sources. Firstly, the traditional approach of critical path scheduling, Basu (2004, p. 129) is to optimize time for completion and secondly derived from the lean tools applied in supply chain management (such as value stream and process mapping) to reduce procurement lead-time and non-value adding activities. 

Extending the vertical liaison downstream to include supphers of major equipment items, generally on the critical path and with long lead times, so as to inject supplier specialist knowledge early into the design, saving time... 

Resilient supply chains may not be the lowest-cost supply chains but they are more capable of coping with the uncertain business environment. Resilient supply chains have a number of characteristics, of which the most important is a business-wide recognition of where the supply chain is at its most vulnerable. Managing the critical nodes and links of a supply chain, to be discussed further in Chapter 10, becomes a key priority. Sometimes these critical paths may be where there is dependence on a single supplier, or a supplier with long replenishment lead times, or a bottleneck in a process. 

Clearly the complexity of most supply networks is such that in reality event management needs to be restricted to the critical paths in that network. Critical paths might be typified by such features as long lead times to react to unplanned events, reliance on single-source suppliers, bottlenecks, etc. 

Time-resolved (fs/ps) spectroscopy revealed that the (singlet) ion-radical pair is the primary reaction intermediate and established the electron-transfer pathway for this Paterno-Buchi transformation. The alternative pathway via direct electronic activation of the carbonyl component led to the same oxetane regioisomers in identical ratios. Thus, a common electron-transfer mechanism applies involving quenching of the excited quinone acceptor by the stilbene donor to afford a triplet ion-radical intermediate which appear on the ns/ps time scale. The spin multiplicities of the critical ion-pair intermediates in the two photoactivation paths determine the time scale of the reaction sequences and also the efficiency of the relatively slow ion-pair collapse ( c=108/s) to the 1,4-biradical that ultimately leads to the oxetane product 54. 

In the scientific method problems are neatly stated, postulates made, data collected, and solutions obtained. Seldom is this path unidirectional. More often, it is a matter of luck and the right combination of individuals at the right time that leads to a solution. Science could not progress without the critical eyes of others. It is often the skeptic questioning the results of other investigators who spurs and... 

---