Diagnostic Resource Planning
A management technique for organisational units whose function consists primarily of diagnostic activities. Adopting this technique improves the efficiency and effectiveness of diagnostic teams by replacing intuition-driven approaches with structured, algorithmic prioritisation.
Two dominant failure modes
Analysis of the current state of play in diagnostic team management reveals two issues that consistently suppress productivity.
"Black box" management
Management adjusts diagnostic resource levels in response to observed outcomes — cost, resolution times, customer satisfaction — but seldom optimises the diagnostic approach itself. Adoption of ITIL creates a false impression of completeness while gaps in diagnostic practice go unaddressed.
Confirmation bias
Diagnostic professionals tend to focus on their preferred working hypothesis and then seek evidence to support it. Once psychologically invested, they may waste effort on unwarranted tests while ignoring tasks that would more efficiently advance or refute other hypotheses.
Diagnostic Resource Planning
DRP answers the core planning question: Given a list of undiagnosed problems, what is the minimal resource cost needed to diagnose all of them?
The framework comprises three interconnected components: the Diagnostic Planning Matrix, the Diagnostic Task Schedule, and a structured reporting layer. Together they replace subjective intuition with objective, algorithmic guidance.
Diagnostic Planning Matrix
Formalise hypotheses and tasks into a structured matrix to identify the optimal next task.
Diagnostic Task Schedule
Schedule tasks across available resources respecting capabilities, availability, and priority.
Reporting
Track resource utilisation and task performance to guide hiring, training, and investment decisions.
The Diagnostic Planning Matrix
A DPM is a two-dimensional table attached to each undiagnosed ticket. It formally captures a diagnostic professional's thinking and provides the data needed for algorithmic prioritisation.
Fred can't print | Printer malfunction | Network malfunction | User PC malfunction | ||
|---|---|---|---|---|---|
Initial Probability | 25.0% | 20.0% | 55.0% | ||
Revised Probability | 0.0% | 19.0% | 81.0% | ||
Diagnostic Tasks | Cost | Effectiveness | Status | ||
Check from another PC | 8.00 | 5✗ | 2✗ | 4✓ | Completed |
Printer panel test print | 10.00 | 4✗ | – | – | Completed |
⇒ Network ping | 4.00 | – | 4 | – | Open |
Examine PC config | 24.00 | – | – | 4 | Open |
Reinstall printer drivers | 108.00 | – | – | 4 | Open |
Wireshark | 150.00 | – | 5 | – | Open |
Completed task total | 18.00 | ||||
Remaining cost estimate | 208.71 | 92.1 % | |||
Estimated final total cost | 226.71 | ||||
Perform indicated task | Network ping | ||||
Cell values (0–5) indicate how useful a task's result would be in assessing each hypothesis. The Indicated Diagnostic Task (IDT) is the algorithmically recommended next task.
Columns: Hypotheses
Each column represents an alternative hypothesis as to the correct diagnosis. Hypotheses must be mutually exclusive and collectively exhaustive. An initial likelihood estimate is made for each, maintained as subsequent diagnostic tasks are completed.
Rows: Diagnostic Tasks
Each row represents a possible diagnostic task, with estimates for completion time, required resources (analysts, equipment, test subjects), and cost derived from resource rates.
Cells: Usefulness Ratings
Each cell holds a rating (0–5) indicating how useful the expected result of that task would be in assessing the corresponding hypothesis. This is the core data the DRP algorithm uses to identify the Indicated Diagnostic Task.
Indicated Diagnostic Task (IDT)
The DRP algorithm analyses the matrix to identify the IDT — the single task that most efficiently advances the diagnostic process given current likelihoods. Focusing on the IDT directly combats confirmation bias.
Value beyond the algorithm
Preparing DPMs provides significant value independent of their contribution to the scheduling algorithm.
Formalised thinking
The act of preparing a DPM forces diagnostic professionals to elucidate their thinking on each ticket, which can clarify reasoning and lead to new insights.
Expected cost of diagnosis
An algorithm assesses the expected total cost of diagnosis from the DPM data, informing decisions about whether to continue pursuing a diagnosis or abandon the effort.
SLA integration
DPM preparation time is consistent across tickets, making it suitable as an SLA metric — e.g., a DPM must be produced within a specified window of ticket creation.
Progress tracking
Updating the DPM as tasks are completed provides a structured, machine-readable record of progress. Reporting tools can process DPM data across the entire ticket set.
Task reuse
Commonly used diagnostic tasks can be stored and reused across DPMs. Tracking tasks over multiple DPMs enables improved time estimates and assessment of historical task effectiveness.
Reduced confirmation bias
By placing focus on the algorithmically derived IDT rather than a preferred hypothesis, the DPM directly addresses the confirmation bias failure mode.
Diagnostic Task Schedule
Once DPMs are attached to diagnostic tickets, the scheduling stage collates resource information and generates an optimised task schedule.
Resource capabilities
Each resource's skill set is recorded, enabling the scheduler to match resources to tasks based on the capability requirements specified in the diagnostic task information.
Availability calendars
For professional analysts, standard work hours are recorded minus leave and other committed time. Externally managed resources — those not directly controlled by the unit, such as hired equipment — have an expected lead time recorded instead.
Priority-respecting algorithm
The scheduling algorithm respects any priority rules mandated in the diagnostic tickets, while favouring IDT completion. Non-IDT tasks may be scheduled when IDT resources are unavailable, preventing resource idleness.
Time-to-resolution estimates
Although only the IDT is typically scheduled, the algorithm can estimate when remaining tasks are likely to occur given resource availability and current hypothesis likelihoods — enabling expected time-to-resolution forecasts.
Performance reporting
The final layer of DRP provides structured reporting to support management decisions about the diagnostic organisational unit.
Resource utilisation
Total time spent on diagnostic tasks, broken down by required resource capability. Informs management as to which capabilities are in greatest demand — guiding hiring, training, or equipment acquisition decisions.
Idle and non-indicated time
The proportion of time a resource spends idle or on non-indicated tasks signals that the resource has lower marginal value than other available resources — useful information for resource allocation and investment decisions.
Ready to apply DRP?
Use the interactive DPM Tool to create and manage Diagnostic Planning Matrices for your undiagnosed tickets.
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