Frequently Asked Questions

Control bound calculation in SLIM-Control

Control bounds

How are the control bounds in SLIM-Control® calculated? Can I change them?

SLIM-Control® ships with a set of pre-defined control bound shapes and widths to help you assess variation of the project actuals from the plan. 

QSM control bound limits typically default to a percentage of the planned total or peak value for the metric being displayed, but you can copy and edit our default control bounds or create your own from scratch! In the custom control bound definition below, the green upper control bound is wider (14% of the planned peak value) than the lower green control bound (11% of the planned peak):

Control Bound Rules

Wider control bounds allow more deviation from the plan before triggering a visual warning. Narrower control bounds provide earlier warning and tighter control. QSM default control bounds vary in width depending on whether the metric being assessed is in rate or cumulative form. Because defect data is typically more variable than other software metrics, control bounds for defect metrics default to twice the width of regular rate and cumulative control bounds. 

Regardless of whether you use QSM default control limits or create your own control bound rules, SLIM-Control’s status icons help you instantly assess the status of various project metrics and take corrective action:

  • When your actual data fall an average of one control bound from the plan, a green status icon lets you know the variation is within acceptable limits. When calculating the average distance from the plan, SLIM-Control® considers all data points but gives more weight to the later data points.
  • When actual data average 1-2 control bounds from the plan, a yellow (warning) status icon is shown. The yellow icon alerts the user that the displayed metric needs to be monitored closely.
  • When the data points average more than 2 control bounds from the plan, a red status icon will be displayed to indicate that re-planning may be needed. The user can generate a new forecast to completion to learn the impact of current deviations upon the delivery date.

The Scoreboard Summary Report can even create an audit trail for key project metrics over time:

Status report

Need more information before making a decision? SLIM-Control’s Snapshot Manager records the status (green, yellow, or red) of various metrics as the project unfolds. This time series view adds context to your analysis: if a “red” metric has consistently lagged behind the plan, it’s probably time to take corrective action. If the same metric has stayed in the green region for the entire project, a red status icon could alert you to a possible data entry error.

SLIM-Control’s customizable control bounds, status icons, and snapshot manager make tracking and monitoring projects a snap!

Taxonomy upgrade extras