This last point in my opinion is ONE major benefit you must seek to extract, if you choose to engage the services of a developer. S/he should be able to help you develop (in_house) expertise needed to maintain the application AFTER s/he is gone. If you fail to ensure this, all your cost_savings from using the application might end up being spent paying the developer to maintain the application over time in the future!
The visiting head of the technical function only needed to look at the most recently plotted point on the chart (relative to preceding ones) for a Key Performance Indicator like. Cost per Hectolitres brewed(One Hectolitre = 100 Litres), to know if the brewery had stayed within the approved upper limit of spend(plotted as a straight line target across the same period) or not. Discussions would then take place based on identified "Exceptions"(which could be "good" e.g. savings made or "bad" e.g. monetary loss due to materials over_used), and "Actions To Be Taken" to correct or maintain observed performances agreed upon.
One Possible Application: Plotting a pie chart based on income contributions from all your products and services(daily, weekly or monthly), and reviewing the automatically computed percentages/visual pie slices, can give very illuminating insight.
The 80ᚼ Pareto principle is based on Pareto's theory that 80% of the results one gets in a particular endeavour will be mainly due to 20% of areas to which one has applied efforts. In business this principle has been found to be true. Your data, properly converted into appropriate performance indicators, will show you where your largest margins come from. You can then channel more time and effort in that direction.