【正文】 Are the sequential relationships among activities correct?Note that time estimates are just that estimates – and, therefore, subject to the problems associated with estimation. Higgins, James: The Management Challenge Basic calculationsSummary of calculations Schierenbeck, Henner. Einf252。 The independent slack time is calculated by assuming that all successors are going to start at the earliest possible time and all predecessors have ended at the latest possible time. Thus, this type of slack time can be used to the full extent without resulting neither in a reduction of slack times of other activities nor in a delay of the whole project.Note that the free slack time at the end and the free slack time at the beginning affect each other. If one part is consumed, the counterpart is not available to its full extent.In project planning, planning is a continuous dynamic process. Thus, replanning is unavoidable. Moreover, for different situations different sequences of actions are optimal. Hence, planning with revisions is referred to as rolling or revolving planning. Laux, Helmut. Entscheidungstheorie, Grundlagen p..273By taking into account the dependencies among activities and their estimated duration, activities that are most likely to bee bottlenecks can be identified. Last, but not least, planning by network is useful to evaluate possible effects of deviations from schedule. Originally, only the effect on time could be evaluated. However, in an integrated system like SAP R/3 effects on other areas such as, ., production capacities can be simulated in real time. Chase R./Aquilano N./Jacobs R. Production and Operations Management: Manufacturing and Services , Hillier F./Liebermann G. Introduction to Operations Research, Sixth Edition After having set up a network, make sure that you perform a final check: The free slack time at the end is calculated assuming that all predecessors have begun at the earliest possible date. Thus, the free slack time at the end calculates, provided the assumption holds, the time the activity can be delayed in order to enable the successor of the activity in question to start at the earliest possible date, too.hrung in die Allgemeine Betriebswirtschaftslehre, p. 159ff They involve costsDifferent kinds of network types have emerged in the field of Operations Research. Starting with deterministic durations and structure, networks with stochastic durations (like PERT) and even stochastic structure (like GERT) offer powerful time planning techniques. However, practitioners are sceptical about the results, and large, plicated project structures require tools which are rather easy to handle. Therefore, we will only discuss Metra Potential Method (MPM) which is used in the PS modul as well. MPM method uses deterministic durations and structures. As a consequence, neither probabilties of, ., a specific duration of the project can be calculated nor can be captured a project structure which has stochastic elements. This would be the case, ., if we wished to model a situation a test could be passed with a certain probability. This would lead to a loop on a MPM structure which is forbidden.A network does not only graphically display the relationships among various activities, it provides also information on the critical path. The critical path indicates which activities are the most critical to be performed in time to avoid delaying the whole project. Higgins, James: The Management Challenge Planning by network is based on the Theory of Graphs. Heinrich, Lutz: Systemplanung MPM uses nodes to represent activities and arrows for their relationships as this is easier to follow. One must know that SAP supports several types of relationships and not only the standard relationship. The following relationships are supported:Finish StartThe preceding activity must finish before the following activity may start.Start StartOne activity cannot start until the other one has started.Finish FinishOne activity cannot be finished until the other one is finished.Start FinishOne activity cannot be finished until the other one has startedFor some activities, the earliest possible start and the latest possible start differs. The difference between the earliest possible start and the latest possible start is called slack time. A slack time greater than zero means that the duration of the activity can be longer than planned without delaying the pletion date of the whole project. The sequences of activities having a slack time of zero are called the critical path. In this context critical means that, if the duration of one of these activities is longer than expected, the pletion date of the whole project is delayed by at least that period of time. One must also realize that there can be several critical paths. Moreover, the critical paths can change during the project as a result of unexpected delays of certain activities. The change of the critical path due to excessive consumption of the slack time is referred to as Parkinson Phenomena. Schierenbeck, Henner. Einf252。 They are processed without interruption They take a certain periods of time Activitiesr EarnedValue AnalysisAll specification activities and Installation II use the 2080 Method for performance measurement. Procurement activities use 0–100 method.Installation I has 3 milestones, viz. Preparation finished (20%), Installation finished (80%), Quality checked (100%). Data for Project RealizationActivityStartEndWorkSpecification of the cabine20Specification of the engine30Specification of mechanical parts20Specification of the control unitProcurement of the cabineProcurement of the engineProcurement of mechanical partsProcurement of the control unitInstallation IInstallation IIExternal Inspection