AAOM Handbook

MS.12 Specify Frequency Distributions, Threats & Opportunities

Context

Each activity that was included in the Scheduling Model had a trigger parameter and trigger tolerance specified for it. The nominal trigger value was used to produce the Baseline Schedule. The trigger tolerance information was used in making adjustments to the scheduling of Activities in order to optimise the Schedule. This optimised Schedule represents only one of many possible outcomes for the actual frequency and timing of the Activities in the schedule. In practice there is a range of potential times at which each Activity could occur, with each time having a different probability of occurring (i.e. the likely timing of an Activity is best represented by a probability histogram). In order to determine the process performance confidence level that can be delivered by the schedule the probability distribution for the Schedule outcomes must be estimated. The range of potential Activity frequencies is one parameter that may influence the process output performance distribution. Where the potential range of frequencies can produce a significant influence on output and resource forecasts these need to be included in the modelling. The most likely case frequency has already been defined in the Baseline Schedule. The probability distribution of possible frequencies around this need to be specified. These estimates do not need to be precise, and the historical records for the Activities, the experience of appropriate personnel and a knowledge intended changes to the either the process, Production strategies or Service strategies can allow these estimates to be made with adequate accuracy. In making the estimates it is necessary to consider what can go well, that will help the best case to be achieved, and what can go badly, to make the worst case occur. If these opportunities and threats are recorded then it is possible to implement some control actions that might increase the probability of a better outcome.

Purpose

To specify the probability distribution for the frequency of the Activities of the Operating Master Schedule.

© McAlear Management Consultants 2006

Operational Planning: Set Operating Master Schedule

Updated: August 2018

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