Constraints overview

After the Lookahead (the 6-week or 8-week plan where activities are broken down into smaller tasks) is generated, you can add constraints to activities in the Masterplan and the Lookahead.

A constraint is work that must be cleared before a task can be done, such as getting site access. This preparation work can relate to contracts, approvals, materials, safety, engineering design, QA/QC or construction submissions.

Constraint types

Lean PlanDo groups constraints into two types:

• Technical Constraint: preparation work such as approvals, permits and design specifications.
• Site Constraint: all preparation work related to the construction site, such as materials, labour, access space and temporary works.

How constraints work

• You can add a constraint to an activity in the Masterplan, or to a task or activity in the Lookahead.
• A constraint shows as a circle on its planned due date, in line with its activity.
• A constraint's status is Done or Not Done. A constraint that is not done shows as a dark grey circle. It turns orange when some of its steps are done, green when it is done, and red when it is overdue and awaits an update.
• If you set a constraint's due date so that the ETA (see below) is not kept, the activity or task is also delayed.
• A constraint can have steps (one part of a constraint). Steps are the small actions or prerequisites that help you manage and finish the preparation work, so work on site can start. A step that is not done shows as an empty circle with a grey outline. A done step is a filled green circle.

ETA and step due dates

• ETA is the number of working days between the constraint's last step and the start of the activity or task. The last step must be due at least that many working days before the start.
• Step due dates must be in increasing order. The second step's due date must be the same as or later than the first.
• The last step's due date is the constraint's due date.