Work Package Structure
A control account is only as good as its work packages. The work package is where all of EVMS becomes tangible — it is the unit where budget is spent, progress is measured, and variances originate. Poor work package definition is the single most common root cause of unreliable earned value data. If you define work packages well, the rest of EVM mostly takes care of itself.
Every work package must have five elements. If any one is missing, the work package is incomplete and will produce unreliable EV data.
| Element | Description | Why It Matters |
|---|---|---|
| Scope Statement | A clear narrative of what work will be performed and what deliverable will result. | Without defined scope, you cannot objectively measure completion. Vague scope leads to subjective EV claims. |
| Start & Finish Dates | Planned start and planned finish tied to the IMS. Duration should not exceed two reporting periods. | Dates drive the time-phasing of budget and enable schedule variance calculation. |
| Time-Phased Budget | Budget spread across the reporting periods the work spans, based on the planned resource profile. | BCWS (planned value) comes from the time-phased budget. Wrong phasing means misleading schedule variance. |
| EV Technique | The method by which earned value will be claimed (e.g., 0/100, milestones, percent complete). | The technique must match the nature of the work. A mismatch creates either premature or delayed EV recognition. |
| Resource Assignment | The specific labor categories, materials, or subcontracts that will perform the work. | Resource loading validates the budget and enables the scheduler to identify conflicts and over-allocations. |
Budget Time-Phasing and Resource Loading
Time-phasing is the process of spreading a work package’s budget across the reporting periods it spans. This is not an arbitrary allocation — it must reflect when the resources will actually perform the work. The time-phased budget becomes the Budgeted Cost of Work Scheduled (BCWS), the “planned value” line against which all performance is measured.
Resource loading is the companion to time-phasing. You identify the labor categories, quantities, and rates needed for the work, then spread those resources across the work package duration. The resulting profile should reflect the natural rhythm of the work: ramp-up, peak effort, and closeout.
✅ Good Time-Phasing
- Budget profile matches the planned resource profile
- Front-loaded for work with early deliverables
- Back-loaded only when the work genuinely occurs late
- Material budget placed in the period of expected receipt or usage
- Subcontract budget aligned with subcontractor milestones
- Total budget equals the sum of all period budgets (no rounding errors)
❌ Bad Time-Phasing
- Budget spread evenly (“flat-lined”) regardless of work profile
- All budget placed in the last period to defer schedule variance
- Budget not reconciled with resource availability
- Material and labor lumped together without distinction
- Budget phased before resources are actually available
- Planning package budget left in periods now within the execution window
💡 Resource Loading Validates the Plan
If you cannot resource-load a work package, you do not understand the work well enough to plan it. Resource loading forces you to answer: Who will do this work? How many hours? In what period? If the answers reveal conflicts — the same engineer is loaded at 150% across three work packages — you have found a planning error before it becomes an execution problem. This is exactly why EVMS requires resource-loaded schedules.
Earned Value Technique Selection
Every work package must have an assigned EV technique — the method by which you will claim earned value as work progresses. Choosing the wrong technique is one of the most common and most damaging CAM mistakes. The technique must match the nature of the work.
| Technique | Best For | Duration | Risk |
|---|---|---|---|
| 0/100 | Short tasks with a single deliverable. Nothing is earned until the work is 100% complete. | ≤1 period | Low — binary measurement eliminates subjectivity |
| 50/50 | Short tasks spanning two periods. 50% earned at start, 50% at finish. | ≤2 periods | Low — slight front-loading but self-correcting |
| Milestone Weighted | Work with clearly defined interim deliverables that can be objectively verified. | Any | Low if milestones are well-defined; high if milestones are vague |
| Percent Complete | Work where progress is continuous but milestones are hard to define. | Any | High — subjective assessment invites the “90% complete” trap |
| Units Complete | Repetitive production or testing with identical units of output. | Any | Low — objective count of completed units |
| Level of Effort (LOE) | Support activities with no measurable output (e.g., program management, sustaining engineering). | Any | None — EV always equals PV; no schedule variance possible |
The golden rule: use the most objective technique the work allows. Prefer 0/100 and milestone-weighted over percent complete. Reserve LOE for work that truly has no measurable output. Every hour of LOE is an hour where EVMS cannot detect schedule problems.
Planning Packages vs Work Packages
Not all work in a control account needs to be planned to the work package level on day one. Work that will be executed in the near term (typically the next 6 months) should be in detailed work packages. Work further out can remain in planning packages — budget holders that have scope and time-phased budget but lack the detailed schedule, resource assignments, and EV technique of a true work package.
Define Control Account Scope
Start with the full scope of the control account from the WBS dictionary and SOW. Identify all the work that must be accomplished and the total budget available.
Detail Near-Term Work Packages
For work starting within the rolling wave horizon (typically 6 months), create fully defined work packages with scope, schedule, budget, resources, and EV technique. These are ready for execution.
Establish Planning Packages for Future Work
For work beyond the rolling wave horizon, create planning packages that hold the remaining budget with approximate time-phasing. The scope is defined at a summary level. No EV technique is assigned yet.
Convert as Execution Approaches
As the rolling wave advances, convert planning packages into detailed work packages. This is an internal replanning action — it does not change the PMB as long as total budget and scope remain unchanged. The conversion should happen before work begins, never after.
💡 The Cardinal Rule
Work must never be performed against a planning package. If actual costs are being charged to a planning package, something has gone wrong in the planning process. Either the work started before the planning package was converted, or the conversion was missed entirely. Both are EVMS compliance violations and both will produce meaningless earned value data.
Common Work Package Planning Mistakes
| Mistake | Consequence | Prevention |
|---|---|---|
| Work packages too long | Subjective EV claims, delayed variance detection, the “90% complete” syndrome | Limit to two reporting periods. Use milestones to break long efforts. |
| Vague scope statements | Cannot objectively verify completion. Arguments about what “done” means. | Every WP needs a tangible deliverable or verifiable exit criterion. |
| Flat-line budgets | Misleading schedule variance in early and late periods. | Align budget phasing with the actual resource plan. |
| Excessive LOE | Hides schedule problems. If 40%+ of your CA is LOE, you are not measuring performance. | Challenge every LOE work package: can this work be made discrete? |
| No planning packages for far-term work | Overly detailed plans that will change, wasting planning effort. | Use rolling wave planning. Detail only the near-term horizon. |
| Planning packages during execution | EVMS compliance violation. No EV can be earned against a planning package. | Convert planning packages to work packages before work begins. |
🎯 The Bottom Line
Work package planning is where EVMS is won or lost. A well-defined work package — with clear scope, realistic time-phasing, proper resource loading, and the right EV technique — produces reliable performance data. A poorly defined one produces noise. Invest the time in planning; every hour spent here saves ten hours of variance analysis later. Next: Budget Baseline Management — how all your work packages aggregate into the Performance Measurement Baseline.
Stop reading, start modeling
Model your process flow, run simulations, optimize staffing with TOC math, and test your knowledge with 107 interactive checks — all in one platform.