How do you explain to leaders who do not have a good understanding of software based systems (or honestly may not care to learn) that software development is not one and done? I need to advocate to keep my software development staff - maybe not the full level but they want to eliminate them.  Any ideas?  I can use analogies but looking for any insights in plain language. 

Can you build a business case to keep them - show the business value the team brings.  If you tie this into revenue, even better.  

Call a meeting and have them take out their iPhones. Ask them how often the apps on their iPhones get updated. Explain why they get updated i.e. new features and bug fixes. Or would they prefer those apps never get updated?

This is why software is not a one and done proposition.

Showcase how a robust software development team can be a unique selling point for the company. The ability to swiftly adapt to market changes and deliver cutting-edge solutions gives the organization a competitive advantage over rivals. Conduct a cost-benefit analysis to showcase the economic impact of retaining a software development team versus eliminating it. Highlight the potential risks and expenses associated with not having a dedicated team, such as increased downtime, security vulnerabilities, and the inability to adapt quickly to market changes.

Use Price and Value to let them know the importance of sw development.

If the price you pay is high, and the value you receive is greater for the sw dev staff.

Then you might receive a lesser price for downsizing the team, but then you’ll have no value at all for what’s important to the business needs.

Think of software not as a one-time project like building a house, but as a continuously evolving product like maintaining a home. Just as a home needs regular upkeep, improvements, and repairs, software requires ongoing maintenance, updates, and enhancements to remain functional, secure, and valuable. Eliminating the software development team after initial creation is like abandoning a house after construction; continuous investment in the software is essential for its long-term success and usefulness.