• Choose a category
• All
• Classic-Fiction

By Root 3175 0

of Throughput transferred through the group each day (Throughput per day or T/D), the group can see how much work is being done and track its contribution over time. Tracking the amount of Throughput delivered per day encourages the group to reduce process flow time and take actions that improve Throughput value; both increase T/D. It would be easy for the PCIP group to report T/D calculated on a monthly basis. Because the PCIP group does not have delivery commitments to other units in the organization, TDD cannot be measured for the group. However, it is still helpful to have a measure of how much the group is contributing to the organization and how well it is doing in fulfilling the purpose for which the group was created.

A second example is the hiring process of the Odessa, Texas Police Department described by Taylor et al., (2003). The department’s hiring process required an average of 117 days and was not hiring sufficient officers each year to maintain the department at the desired strength. The TOC TP were used to identify what to change, what to change to, and how to cause the change, but the impetus for starting the process was awareness of the shortfall in the hiring department’s production relative to its goal of hiring an adequate number of officers each year. Although the department did not use such a measure, it is easy to see how the department could have used a measure similar to T/D to monitor its progress. In this case, “officers hired per month” would have been useful to make senior management aware of the progress of the hiring department in meeting its goal of hiring sufficient officers to maintain the required strength of the police department.

The definition of Throughput suggested in the TOCICO Dictionary (Sullivan et al., 2007, 47) in these two examples is “the rate at which the system generates ‘goal units. ‘” (© TOCICO 2007, used by permission, all rights reserved.) Even departments that do not have a direct impact on Throughput can define goal units to monitor their progress. Typically, T/D is calculated as the number of goal units delivered over the reporting period divided by the number of days in the period. T/D encourages groups to move quickly to complete larger Throughput value work sooner. In addition, it encourages shortening the flow time of all work, especially the lower Throughput value tasks.

Any organizational unit should be able to determine its goal units and calculate a T/D. This measure helps unit management stay focused on the unit’s goal, but some units could also benefit from another measure, described next.

Inventory Dollar Days

We can borrow another supply chain measure, Inventory Dollar Days (IDD), to help the PCIP group and the Odessa Police Department monitor their progress by focusing attention on the number of projects released into the system before there are sufficient resources to process them. The traditional definition of IDD applies to physical inventory. Inventory Dollar Days (IDD) is defined in the TOCICO Dictionary (Sullivan et al., 2007) as IDD is computed as the sum of all current inventory on hand valued at the original purchase price times the number of days since the inventory was received by the unit being measured.

(a) measure of the effectiveness of a supply chain that measures whether the supply chain did things that it shouldn’t have done, the result of which is that the supply chain is holding inventory of products customers don’t want. The system should strive for the minimum IDDs necessary to reliably maintain zero throughput dollar days. (© TOCICO 2007, used by permission, all rights reserved.)

Effective use of DBR and eliminating efficiency as a performance measure at non-constraints obviate the need for measuring IDD for physical inventory within the organization. However, we can redefine IDD to help with “conceptual inventory.” For some groups that have no physical inventory but have a flow of small projects, assignments, papers, or mental tasks, it would be helpful to just count the number of such items in progress and measure