What is this tool intended for?

The SIMBA Cost Model is Designed to help existing and prospective Black Soldier Fly (BSF) operators assess the financial viability of setting up or running a SIMBA-scale facility. Its primary purpose is to estimate one-year cost-revenue balances for two operational units: a Grow-Out Unit, which handles the bioconversion of organic waste by BSF larvae and the harvesting of larvae and frass; and a Reproduction Unit, which manages the BSF lifecycle from eggs through to seven-day-old larvae (7-DOL) ready for transfer to the grow-out phase. The tool can be run for either unit independently or for both units in combination, with a combined results sheet that consolidates costs, revenues, and saved costs across the full SIMBA operation.

The tool is specifically scoped to the SIMBA scale of operations: part-time, labour-based, simplified BSF conversion systems treating between 50 kg (Grow-Out only) and 250 kg (full combined system) of organic waste per week. It is not intended for large-scale or highly mechanized industrial BSF facilities.

How does this tool work?

The main version of the tool is structured as a macro-enabled Microsoft Excel workbook (.xlsm) with colour-coded input cells: yellow cells contain editable default values derived from the SIMBA standard operating procedures, while orange cells require the user to select an option from a dropdown menu. All key default values can be overwritten with facility-specific data to improve accuracy.

The workbook is organized into the following main sheets:

•        Welcome: Allows the user to select the local currency (from a list of approximately 150 country currencies) and choose which unit(s) to model.

•        Reproduction Unit overview: Displays a summary of performance indicators (egg production, larval yields, pupation rates) alongside a profit summary after one year, covering investment costs, wear-and-tear (depreciation), operating costs, and sale revenues.

•        R. Investment Costs: Itemizes capital expenditure for the reproduction unit, including building and civil works (e.g., a 30 m² roofed structure with default material quantities and costs) and all required equipment (love cages, nursery containers, hatchling boxes, scales, etc.), with editable unit costs and lifetimes used to calculate annual depreciation.

•        R. Operating Costs: Captures weekly and annual costs for larval Feed, substrate, labour, repairs and maintenance, utilities, transport, marketing, and consumables. Default values assume zero substrate and labour costs (i.e., self-sourced waste and unpaid household/farm labour), which can be adjusted.

•        R. Revenue: Estimates income from the sale of 7-DOL larvae and frass produced by the reproduction unit, with adjustable sale prices per gram or kilogram.

•        Grow-Out Unit overview: Mirrors the structure of the reproduction unit summary, with performance indicators (bioconversion rate, larvae and frass yields per week based on substrate type and quantity) and a one-year profit summary.

•        GO. Investment Costs: Lists equipment for the grow-out unit (pre-treatment tools, grow-out containers, sieve, storage buckets) with editable amounts and lifetimes. Building costs default to zero, as the SIMBA guide assumes an existing or shared roofed space.

•        GO. Operating Costs: Covers the cost of purchasing 7-DOL larvae (if not self-produced), substrate costs, labour, and other operating expenses.

•        GO. Revenue: Captures revenues from selling fresh or dried larvae and frass, plus saved costs — a distinctive feature of the tool that quantifies the value of replacing conventional purchased animal Feed and chemical Fertilizer with BSF-derived products. Default assumptions use a 1:1 substitution ratio.

•        GO & R Results: A combined summary sheet showing the total investment, wear-and-tear, operating costs, revenues, and saved costs across both units, with a final profit figure both including and excluding first-year investment costs.

A key Design feature of the tool is the separation of profit including investment costs (a more conservative first-year estimate) from profit excluding investment costs (which reflects the ongoing annual financial position after the initial capital outlay, since investment costs are a one-time expense). Annual depreciation is included in both calculations.

Who might use this tool and with which types of stakeholders?

The primary users of the SIMBA Cost Model are:

•        BSF farmers and small-scale entrepreneurs in low- and middle-income countries who are considering starting or expanding a SIMBA-scale BSF facility and need to assess financial feasibility before committing capital.

•        NGOs, development organizations, and extension services supporting BSF enterprise development among smallholder farmers or community groups, who need a simple financial planning tool they can use with beneficiaries.

•        Agricultural and rural development advisors helping farmers evaluate whether integrating a BSF unit into existing farm operations (e.g., poultry or fish farming) makes economic sense given local Feed and Fertilizer prices.

•        Project developers and donors assessing the financial sustainability of SIMBA-based interventions as part of project Design or monitoring.

•        Researchers and students conducting economic analyses of insect-based bioconversion systems at small scale.

What stages of a process can this tool support?

The SIMBA Cost Model primarily supports the pre-investment planning and pilot Design stages of a BSF project:

•        Feasibility and pre-investment Assessment: Helps operators estimate whether a SIMBA facility is likely to break even or generate profit under local cost and market conditions before any capital is committed.

•        Business planning and strategy: Supports the development of a business plan by generating one-year financial projections that can be adjusted across multiple scenarios (e.g., with and without paid labour, with different substrate types, with varying product sale prices).

•        Pilot evaluation: Can be used retrospectively or in parallel with an ongoing pilot operation to compare expected versus actual financial performance, identify cost drivers, and refine projections for scale-up.

•        Capacity building: The structured, colour-coded input format makes it suitable for use in training workshops where operators learn to plan and manage their BSF finances.

What skills, capabilities and resources are required to use this tool?

Users need access to a computer with Microsoft Excel and must enable macros when opening the file. Basic familiarity with Excel is sufficient; no advanced financial modelling or programming skills are required. The colour-coded cell system and pre-filled SIMBA default values make the tool accessible to practitioners with limited accounting experience.

To use the tool effectively, operators benefit from having basic knowledge of their own operational parameters, including: the quantity of waste they intend to process per week, the types of substrate available and whether they involve any cost, whether they plan to employ paid staff, local prices for BSF-derived products (fresh larvae, dried larvae, frass), and local prices for conventional animal Feed and Fertilizer that BSF products could replace. Where these data are not available, the SIMBA guide default values provide a reasonable starting point.

An internet connection is not required once the tool has been downloaded.

Where can this tool be used?

The tool is globally applicable. The currency selection sheet covers approximately 150 countries across Africa, Asia, Latin America, Europe, and beyond, allowing users to work in their local currency. The default performance indicators and cost structures are calibrated specifically to the SIMBA approach as documented for low- and middle-income country contexts, with particular relevance to sub-Saharan Africa and South/Southeast Asia, where decentralized, labour-based BSF operations are most common.

Because substrate type, equipment costs, labour costs, and product prices vary significantly by location, the tool is Designed to be customized: users are expected to replace default values with locally appropriate figures to generate meaningful projections. The tool is most useful in settings where BSF operations are at the small-to-medium scale (50–250 kg waste per week), with mainly manual or semi-mechanized operations.

Case examples of where this tool has been used

The SIMBA Cost Model was developed by Eawag as part of the SWIFT project (Sustainable Waste-based Insect Farming Technologies, funded by SOR4D). The default values in the tool are grounded in operational data from SIMBA pilots and the SIMBA standard operating procedures tested in Uganda, Ethiopia, and Côte d'Ivoire. The tool is referenced in the BUGS Africa Operators Toolkit (CCAC, 2025) as the recommended financial planning instrument for operators considering the Feed and frass production or self-use Business models at SIMBA scale.