Agent Time Accounting Model
Agent Time Accounting Model is the ledger in which a workforce function accounts for every paid minute of its agents: six nested tiers, from paid time down to in-work time by channel, with the rule that each minute lands in exactly one bucket and the identity that the buckets plus a published residual sum back to paid time. It matters because shrinkage, occupancy, utilization and the roll-up from workload to full-time equivalents are all ratios of tiers of this ledger, and a function whose ledger does not close is computing those ratios on denominators that disagree with each other by an amount nobody has measured. The model is part of the Workforce Data Definitions Framework; it defines no metric of its own. Shrinkage, Occupancy and utilization keep their definitions on their own pages and in The Definitions Register; this page states which ledger tiers each is a ratio of, so that the three are computed from one set of numbers.
The ledger follows the practitioner planning chain in which required staff on the queue is grossed up through rostered staff to paid staff by the activities that remove people from it,[1][2] and it applies the principle that a number has no meaning apart from the procedure that produces it:[3] each tier names the instrument that stamps it. The ledger exists so that asynchronous and concurrent work, which the telephony platform cannot see, is accounted on the same object as voice time rather than left to inflate an available state.
The six tiers
Each tier is a subset of the one above it, and the difference between adjacent tiers is itself a named bucket, which makes the ledger a partition rather than a list of overlapping measures.
| Tier | What it holds | Instrument (class, never a product) | What leaves between this tier and the next |
|---|---|---|---|
| 1. Paid time | Hours the employer pays for in the period, including paid absence | payroll or time-and-attendance system; for partner supply, the invoiced hours | off-schedule paid time: paid leave, paid sick absence, paid public holidays, paid training days not on the roster |
| 2. Scheduled time | Hours the workforce system rostered the agent to work, by activity | the workforce-management system's published schedule | scheduled-not-logged time: absence against a scheduled shift, late start, early finish, no-show |
| 3. Logged-in time | Hours the agent was signed in to a work platform | the telephony platform's session log; for agents on no telephony queue, the work-item tool's session log | unaccounted state time: logged minutes that carry no state, or a state not in the dictionary |
| 4. State time by code | Logged time partitioned by the activity code the agent or system set | the telephony state log, translated through the dictionary of Activity-Code Consistency | non-productive states: break, training, coaching, meeting, system-down and the other planned and unplanned shrinkage classes |
| 5. Productive time | State time in codes whose class is productive: available and in-work on any channel | derived from tier 4 by the code's class attribute | available-idle time: productive time with no contact, session or item in hand |
| 6. In-work time by channel | Time attributable to a unit of work: talk, hold and after-contact work for voice; focus time per session for chat; touch time per item for asynchronous work | telephony contact records; chat session logs; work-item timers or desktop capture (Email Handle Time Measurement) | nothing; this is the floor of the ledger |
Tiers 1 to 3 are stocks of hours held by three different systems; the gaps between them are the subject of Headcount Reconciliation in Service Operations at the population level and of this page at the minute level. Tiers 4 to 6 are partitions of one system's hours, and the gaps between them are definitional: the dictionary says whether a state is productive, and an instrument either stamps a unit of work against a productive minute or does not.
The closure identity
The ledger closes when
- paid time = Σ (bucket time) + residual
where the buckets are the leaf nodes of the tiers above: off-schedule paid time, scheduled-not-logged time, each non-productive state class, available-idle time, and in-work time for each channel. Two rules make the identity a control rather than an aspiration.
Every minute lands in exactly one bucket. The buckets are mutually exclusive and, with the residual, exhaustive. A minute two systems claim (a telephony in-work minute a work-item timer also claims) is assigned by the precedence rule on Agent State Taxonomy and Activity Codes, never left in both; a minute no system claims is residual, never absorbed into the nearest bucket.
The residual is a published measure. It carries its own row in the function's reporting, with a tolerance set locally and a grade from Human Gates and Number Grades. A residual outside tolerance fails the sum-to-paid test on Reconciliation Tests for Time Accounting and blocks the metrics computed from the affected tiers; a function that reports shrinkage to one decimal place and cannot say where two percent of paid time went has reported the decimal and not the two percent.
Metrics defined on the ledger
Definitions stay on their own pages; the table states which tiers each ratio reads, so that a change to a tier's instrument is recognized as a change to every ratio reading it.
| Metric | Register entry | Numerator tier | Denominator tier | Defined on |
|---|---|---|---|---|
| Shrinkage | SHR-01 |
paid time minus productive time (tiers 1 − 5) | paid time (tier 1), or scheduled or logged time where the register's denominator question is settled otherwise | Shrinkage |
| Occupancy | OCC-01 |
in-work time (tier 6), summed across channels with concurrency handled as the register states | productive time (tier 5), as Occupancy defines it; OCC-01's open question may move it |
Occupancy |
| Utilization | no register entry; computed on the ledger | in-work time (tier 6) | paid time (tier 1) | Agent Utilization vs Occupancy Definitions and Tradeoffs |
| Handle time | AHT-01 (session channels) / AHT-02 (asynchronous) |
in-work time per channel (tier 6) | handled units on that channel (CON-01) |
Average Handle Time |
The register's open question for SHR-01, whether the denominator is paid, scheduled or logged hours, is a choice of tier, and the ledger makes the three answers computable side by side. This page uses utilization = in-work ÷ paid, as the comparison table on Occupancy does; the live utilization page defines it as productive ÷ paid, which equals 1 − shrinkage on a paid denominator, and the register records which form the function adopts. The survey literature on call-center operations treats agent time in the same nested way, with the utilization of the queue's servers a quantity inside a larger accounting of staff.[4]
Worked example
The numbers are synthetic, graded [E]; ratios computed from them are [C] on [E] inputs and inherit that grade. Ten agents, one day, 8.0 paid hours each: paid time 80.0 h [E].
| Bucket | Hours [E] | Tier gap it belongs to |
|---|---|---|
| Paid leave (one agent, full day) | 8.0 | paid − scheduled |
| Paid sick absence against a scheduled shift (one agent) | 8.0 | scheduled − logged |
| Late starts and early finishes (eight agents) | 1.5 | scheduled − logged |
| Breaks (planned shrinkage) | 4.0 | logged, non-productive |
| Training, coaching and team meeting (planned shrinkage) | 3.5 | logged, non-productive |
| Voice in-work: talk, hold, after-contact work | 31.2 | productive, in-work |
| Email in-work: work-item touch time | 9.6 | productive, in-work |
| Chat in-work: focus time across sessions | 6.1 | productive, in-work |
| Available-idle | 7.4 | productive, not in-work |
| Σ buckets | 79.3 | |
| Residual (logged minutes in no dictionary code) | 0.7 | published; 0.9% of paid [C] |
| Paid time | 80.0 | closes |
The tiers: scheduled 72.0 h, logged-in 62.5 h, productive 54.3 h, in-work 46.9 h, all [C]. Reading the register's ratios on them, with the residual counted as non-productive until explained: shrinkage on a paid denominator (80.0 − 54.3) ÷ 80.0 = 32.1% [C]; occupancy 46.9 ÷ 54.3 = 86.4% [C]; utilization 46.9 ÷ 80.0 = 58.6% [C]. Had the 9.6 email hours been worked inside a voice available state, as Production Accounting for Blended Agents describes, the ledger would show in-work 37.3 h and available-idle 17.0 h, occupancy would read 68.7% [C], and a voice requirement model would conclude the team was overstaffed by the email workload it could not see.
The ledger as the object everything reconciles to
Every page in the framework reads or writes this ledger. Agent State Taxonomy and Activity Codes says which state puts a minute in which bucket. Workload Units and the Roll-Up to FTE walks the tiers upward from in-work time to paid time and full-time equivalents, and a roll-up that cannot be walked back down to the ledger's actuals has an unexplained factor in it. Reconciliation Tests for Time Accounting is the test suite on the identity. The Source of Truth Register names the system of record for each tier, and The Definitions Register holds the ratios. The practitioner texts describe the same chain as planning factors applied to a requirement; the framework insists it be an accounting identity on measured tiers.
Maturity Model Position
Four scales on this wiki use the word level; the launch page states which is which. On the WFM Labs Maturity Model™ the ledger is a Level 2 object at tiers 1 to 3: a function that can state paid, scheduled and logged hours from three named systems and publish the gaps has a ledger, however the lower tiers are filled. Tiers 4 and 5 with a dictionary and a published residual mark Level 3 and are the precondition of the automation layer. Tier 6 measured per unit of work on every channel, with the closure test run on every extract rather than at month end, is typical of Level 4, where intraday automation reads the same ledger the capacity model does.
See Also
- Workforce Data Definitions Framework — the hub this ledger belongs to
- The Definitions Register — the ratios the ledger's tiers are read into
- Agent State Taxonomy and Activity Codes — which state puts a minute in which bucket
- Reconciliation Tests for Time Accounting — the tests on the closure identity
- Workload Units and the Roll-Up to FTE — the ledger walked upward from workload
- Shrinkage — the paid-to-productive gap, defined there
- Occupancy — in-work over productive, defined there
- Time and Production Accounting Audit (generic process) — the top-to-bottom audit of every capture point into this ledger
References
- ↑ Reynolds, P. (2003). Call Center Staffing: The Complete, Practical Guide to Workforce Management. The Call Center School Press (the chapters on shrinkage and the rostered-staff factor).
- ↑ Cleveland, B. (2012). Call Center Management on Fast Forward: Succeeding in the New Era of Customer Relationships, 3rd ed. ICMI Press, part 3 (staffing and the rostered staff factor).
- ↑ Deming, W. E. (1986). Out of the Crisis. MIT Press, chapter 9 (operational definitions).
- ↑ Gans, N., Koole, G., & Mandelbaum, A. (2003). "Telephone Call Centers: Tutorial, Review, and Research Prospects". Manufacturing & Service Operations Management 5(2), 79–141.
