Estimating costs and preparing budgets for any engineering project is a difficult process, especially trying to straddle the line between detail and simplicity. However, an accurate estimate is required and there is only so much detail that can be modeled in an Excel spreadsheet. For FTTH rollouts, accuracy can be significantly impacted the more complicated the architecture and the further removed an area is from the model's assumption of location characteristics. These complexities are amplified when the analysis is being performed on non-contiguous regions and when budget conclusions are being drawn on each region individually.
Biarri Networks recently had the privilege to assist one of our customers in this budget estimation process, as the builds on the periphery of the network did not meet their budget expectations. Analytically, this made sense, the edges of a network rollout will contain far more edge-case service locations and situations where a unique and expensive build is required.
Automated network design allows for accurate network estimates while still accounting for all the complexity required. At Biarri Networks the same underlying algorithms and software are used to complete feasibility, high-level, or detailed designs; the varying level of design detail comes from how much additional data is introduced by the network planner.
By automating the evaluation of duct capacity and pit/vault utilization, in addition to the standard network connectivity quantities seen in feasibility designs, we can closely align them with the more detailed stages that follow later on design constraints, such as prioritizing cabinet locations for safe working conditions, which typically do not significantly affect the overall cost of a network. Therefore, when these constraints are overlooked during the feasibility design phase, there is generally no substantial alteration to the Bill of Material outputs.
During this recent budgeting exercise, Biarri Networks produced cost estimates for a portion of the proposed rollout area (>100k HHP estimated across ~700 separate design areas). Because this was a brownfields deployment, estimation of civil remediations was required alongside the usual network equipment counts and footage. Several of these areas have since had their detailed designs completed allowing for a comparison of the estimated and actual values.
| Category |
% of estimated material required for detailed design |
| Existing conduit reuse |
90% |
| New conduit required |
82% |
| Pit remediations required |
93% |
| Drop cable lengths |
104% |
| Terminal tail cable lengths |
96% |
| Access cable lengths |
90% |
| Multiports |
90% |
Two main deltas stand out in the comparison, the slight overestimate of most materials and activities, and the minor underestimation of drop lengths. Both are due to a more aggressive use of existing fiber equipment in the detailed design leading to longer drops reaching existing multiport and a reduced need for upstream equipment and cables. The specifics of this project necessitated a gap in the available data between budgeting and design, however, the outcomes clearly highlight the need for data that is as accurate as possible. Although this is required for all levels of design detail, the effects are far more pronounced during a feasibility analysis where human input is removed.
Key Takeaways
- Biarri Network's algorithmic approach to design generates highly accurate initial designs without human intervention but can be reliant on the underlying data quality.
- Budgeting of complex areas requires a level of detail that is unable to be obtained through non-design methods of modeling.
- Biarri Networks has a proven track record of providing accurate designs and estimates which is shown in the customer’s project above.