Improving Systems Engineering Effectiveness Using Kanban-Based Scheduling and a Service-Oriented Approach

Work Item Selection Policies
―Rules for selecting the next work item from the backlog or a ready queue when an activity has less work than its WIP limit; depends on both Class of Service and Value Function, and leads to specific flow behaviors.
• Class of Service
―Provides a variety of handling options for work items. May have a corresponding WIP limit for each activity to provide guaranteed access for work of that class of service. CoS WIP limit must be less than the activity’s overall WIP limit. Examples are expedite, datecertain and normal. CoS may be disruptive (such as expedite) and is the only way to suspend work in progress.
• Value Function
―Estimates the current value of a work item within a CoS for use in the selection algorithm. Can be simple (null value function would produce FIFO) or a complex, multiple kanbansystem, multi-factor method considering shared scarce resources and multiple cost/risk factors. The means of prioritizing work items. There may be multiple value functions that return independently established values for each hierarchical layer within the KSS For example, in SE, the overall systemic value of a work item may differ from the one that the project-level value function would return.