FEL is the discipline of getting a project defined before it gets executed. The CII has shown repeatedly, across hundreds of industrial projects - that the quality of front end planning is the single strongest predictor of cost, schedule, and operability outcomes. This page lays out how we use Logic Diagrams as the working tool for early framing.
CII's Front End Planning research (notably RS213-1 and the PDRI tool family) has consistently shown that projects which complete robust front end loading deliver, on average, with materially lower cost growth, less schedule slip, and far fewer change orders than those rushed into execution.
FEL is not a single deliverable - it is a staged conversation: from business case, to scope framing, to enough definition that a sanctioned budget and schedule can credibly be set. Each stage gate exists to ask the same question: do we know enough yet to spend the next tranche of money?
FEL is often confused with "early scheduling" - and teams reach straight for a detailed Primavera P6 schedule before the scope is even framed. That schedule then becomes a commitment nobody can defend.
The Logic Diagram tool here is deliberately not a full project planner. It is for initial framing of core elements and sequences - the boxes and arrows you need to test whether the strategy hangs together, before any L3/L4 schedule is built.
One of the most common reasons FEL stalls is that teams blur these two roles together. The same team often performs both - but the mode of thinking is fundamentally different. One is execution-focused and convergent (Delivery); the other is exploratory and divergent (Planning). Make sure there is clarity on what you are doing. Developing an MTO during FEL3, is not the same planning on how that MTO will be purchased during execution.
The team is inside a FEL stage (FEL-1, FEL-2 or FEL-3) and needs to drive it to its gate decision. The work is concrete: studies, options evaluations, basis-of-design documents, deliverable registers, gate-readiness reviews. This is the core to delivery. Defined scope, baselined schedule, tracking progress, costs, foreacsting.
Tools that fit: deliverable registers, weekly progress, the Interfaces app, L3/L4 schedules for the current phase only.
In parallel, the team must look past the current gate and frame the next phases - and ultimately execution. This is strategic shaping, not detailed delivery. The output is a plan for what comes next.
Tools that fit: milestone tables, Logic Diagrams (this app), L2 Gantts, or a Level 3 CPM schedule at the right granularity. The form matters less than the milestone alignment underneath it.
Milestones first, fidelity second. The most critical output of Role 2 Planning is not a schedule - it is an agreed set of overall milestones for the next phase. How those milestones are expressed is secondary, and there is no single right answer. A simple milestone table, a Level 2 logic diagram, a Level 2 Gantt, or a Level 3 CPM schedule (at varying granularity) can all carry the same underlying commitment. Pick the form that matches the clients requirements and aligns to the complexity of the project.
The full baseline schedule is built at the beginning of the phase, not before it. Building the detailed CPM Level 3 schedule for the next phase is genuinely an artform - the level of detail, the breakdown, the calendars, the logic density. In practice, the full delivery schedule that will actually be baselined and managed against is only agreed during the first 2–4 weeks of the phase itself, as part of project setup. Until that baseline is set, every version is a continuously developing schedule model - useful for alignment, not yet a contractual commitment.
The diagram on the right shows the typical role distribution across FEL-1, FEL-2 and FEL-3. Notice how the centre of gravity shifts - business and strategy lead the early framing, technical and project disciplines take over as definition matures, and execution planning intensifies as FEL-3 closes.
The same individuals often appear across phases, but the weight of their contribution moves. Recognising that shift is what stops a project from accidentally executing in FEL-2 or still framing in FEL-3.
A logic diagram is a low-fidelity, high-clarity sketch of the work: blocks for major scope elements, arrows for sequence, light annotation for duration and dependency. It is deliberately coarse - and that is its strength.
This diagram is the kind of artefact Role 2 produces during the close-out of FEL-2 or the kickoff of FEL-3. The blocks are scope chunks (studies, design packages, reviews); the arrows are sequence, not dates.
It deliberately fits on one page. If your FEL-3 plan needs a wall of P6 bars before it can be discussed, the strategy isn't yet clear enough to execute.
Build one like thisOnce the Logic Diagram is stable, the same blocks can be laid against a timeline to give leadership a sense of duration and overlap. We don't have a dedicated app for this conversion yet, but the picture on the right is what the FEL-3 logic above looks like rendered as a coarse Gantt.
Note: this is still a framing Gantt - bars are weeks, not days; there are no resources, no calendars, no contractual commitments. It is meant to be argued with, not signed.
FEL phases don't need a Level 3 control schedule to be run well. In fact, most of the deliverables in FEL-1 to FEL-3 sit comfortably at Level 2 summary detail - packages, reviews, gate documents. Our Level 2 Progress app is built precisely for this granularity: enough rigour to commit to a date, light enough not to bury the team in scheduling overhead.
CII's body of work on FEP - including the PDRI tools (Industrial, Building, Infrastructure, Small Industrial) and Implementation Resource IR113-2 - frames front end planning as a staged definition exercise. Logic diagrams play a specific role at each stage.
A non-exhaustive list of CII publications that inform how we treat FEL on this platform. Consult the source documents directly for full context and licensing.
The foundational research linking FEP effort to project outcomes.
Use for: the business case for spending real money on FEL before sanction.
An implementation guide covering the PPP process step-by-step.
Use for: templates, roles, and the deliverable list each FEL stage should produce.
Scoring tools for Industrial, Building, Infrastructure and Small Industrial projects.
Use for: objective scoring of how well-defined a project is at the FEL-3 gate.
PDRI, RS213-1, IR113-2 and related materials are publications of the Construction Industry Institute (CII). References here are for educational comparison; consult the source documents for authoritative requirements and licensed use.
Start a Logic Diagram for the next phase or for execution sequencing. Keep it coarse, keep it honest, and let it evolve as your front end matures.