Which works have a hard window?
A hard window is a period in which a piece of work can be done at all, or can be done without damage, and the calendar does not move it. In solar and wind construction the common ones are these.
- Ground works and piling, which need soil firm enough for a rig and for the piles to hold.
- Cable trenching and cable pulling, where wet ground and cold weather make the trench and the cable harder to handle.
- Access roads that must carry heavy deliveries through a wet season, and the crane pads for the modules, trackers and inverters.
- Environmental restrictions, such as breeding or nesting periods that stop works near a protected habitat.
- Outage windows set by the network operator, when the grid connection can be cut for the tie in and the energisation tests.
Why does one missed window cost a season?
A missed window is not a small delay. If piling is not finished before the ground turns wet, the next dry period may be months away, and the tracker installation and the commissioning that depend on it move with it. The cost is also in the crews and cranes that were booked for the window and now stand idle, and in the access roads that must be repaired before the work can restart.
Projects often see this only when the forecast for the piling reaches the end of the dry period. By then the choices are expensive. The decision that would have saved the season was usually available a few weeks earlier, when the progress was still on the plan.
How do you put a window into the schedule?
Enter the window as a planned date on the milestone it protects, not as a note in the phase. A piling milestone with a planned start in the first dry week and a planned end before the window closes tells the office what the plan assumes. Leave a margin of working days before the window closes, and say in the milestone note what the margin is for, such as a wet week or a rig breakdown.
Reperline does not hold a calendar of weather or of the operator's outage dates. The window exists in the project only once it is entered as dates, with its source noted, such as the network operator's outage plan or the EPC contractor's programme. For the basics of a planned date and a milestone, the schedule module shows how each one is set.
How do you read a forecast against a window?
Reperline builds a linear forecast for a milestone from its start, the time spent and the share done. For a milestone inside a hard window, the forecast is useful only if the window's end is entered too. A forecast end more than 7 days past the planned date raises a signal, but a milestone can still finish after the window closes while sitting inside its own plan. So read the forecast against the window's end, not only against the planned date.
When the forecast is later than the window's end, the decision belongs to a person, and it should be made while the window is still open. Enter the forecast date with a note giving the reason, so the choice sits next to the milestone it affects.
What decisions belong inside the window?
Most of the value of a window is in the weeks before it closes. The questions below are the ones that still have an answer while the ground is workable.
- Whether to add a second rig or crew while the ground is still firm.
- Whether to bring forward the cable pulling that depends on a finished trench, or to hold it until the trench is ready.
- Whether to order temporary matting or stone for the access road before the wet season starts.
- Whether to ask the network operator for an earlier outage slot, or to accept the next one and plan around it.
- Whether an environmental restriction has a start date earlier than the plan assumes.
How do site facts show a window closing?
A window closes slowly, in small percentages. A piling phase that adds a few percent each week and then stops is the early sign. Site facts carry the percent done, the date of the work and photos of the ground, so the office can see the trend rather than a single figure. Reperline raises a signal when an active phase has no new fact for 7 days, and silence in the middle of a dry period deserves a call on the same day.
Dated facts also give the office a record to use when the window's end is discussed with the contractor or the network operator. The record shows what was done, when it was done and what the team reported at the time, which is more useful than a summary written after the window has closed. For the supply side of the same problem, read long lead items, and for reports from a site with no coverage, read remote site progress reporting.
How do you review windows each month?
A monthly review of the windows takes less time than a site visit, and it catches a window that is slipping while there is still room to act. Go through the hard windows in the project one at a time, and ask four questions of each. Is the milestone inside the window in the plan? Is the forecast end before the window's end? Is there a fact from the last 7 days? Is there a decision still open? Write each answer on the milestone with the date and the name of the person who gave it, so the next review starts from the record and not from memory.
Windows that fail the first two questions go to the top of the list, and the decisions above are worked through for them while there is still time. A window that passes all four can wait for the next review, and the notes show why.
Where do monitoring systems fit?
Reperline does not replace SCADA, monitoring or dispatch systems. Once the plant runs, those systems watch the output and the grid. Reperline keeps the construction plan, the site facts and the decisions up to the stages that lead to energisation. Whether a piece of work fits its window is a question the schedule can answer only once the window has been entered as dates.
The energy projects page describes how Reperline is used on this kind of project, and the signals module lists the warnings the office receives. Plans start at €39 a month per project, with a 14 day free trial and no card needed, on the pricing page.