Bottom-up Planning

Bottom-up Planning explained

Start with a shared planning framework: which task needs solving, which outputs are required and which constraints apply? Participating teams estimate their work on that basis. Without a common scope, seemingly precise numbers describe different assumptions. Record prerequisites, uncertainty and work that is still missing.

Combining estimates involves more than addition. Two teams may have planned the same task or need the same specialist at the same time. Some work can run in parallel; other work requires approval or a completed input. Effort and calendar duration are therefore different quantities. Include review, handover and ongoing maintenance where these belong to the agreed scope.

Bottom-up and top-down are different planning directions that can be combined. Estimates can be compared with a specified deadline or budget. If they do not fit, decide on scope, sequence, resources or the objective. Quietly reducing an estimate until it fits the constraint does not resolve the conflict.

Proximity to delivery provides useful knowledge but does not prevent estimation errors. Compare subsequent experience with documented assumptions and improve the next plan. Use software when it makes shared visibility and updates easier; a traceable spreadsheet may suffice for a manageable project. What matters is making changes and their consequences visible.