Better than chiseling on a stone tablet, though less reliable.
Oh so many things:
Database is SLOW
No user workflows, cannot require approvals, checks, releases, etc.
No ability to limit access to fields, or to require approvals on data entry
Fields are not updatable in table views and require opening a screen for each item to update.
Finding information in Sage is difficult, must search through multiple screens, reports, or excel spreadsheets to find date
Order data exists in many separate views (SO, PO, WO, Invoice) without a single summary view of status.
Sage50 items do not link – a line on a PO, SO, Quote, etc cannot be clicked to bring up the item card. The ID must be memorized and typed into another window, wasting valuable time
Data import/export from/to Sage50 is time consuming and error prone
Document templates are stored locally and must be manually updated per machine on change.
One time use items or BOMs have to be added to part master to never be removed which clutters system, or have to be entered as a description items which severely limits usability.
Cannot open multiple records when reviewing order history (or item cards, POs, Invoices, etc). Can only have one window for each type open at a time.
No system discount levels
Difficult to determine lead times for an assembly, have to start a pseudo work ticket and still can only determine current part availability that doesn't show when on order parts will arrive
Sage can assign a user to a quote, but has no notifications to tell that user when the quote gets converted, updated, etc
No material traceability, or lot tracking
Routings do not exist – cannot track inventory moves from receipt to, inventory, picking, assembly, QA, etc
Sage50 cannot record who received, assembled, tested, shipped, etc
Cannot attach records or files to built items (final inspection reports, pictures, etc)
Purchase planning is almost non-existent.
Parts cannot undergo true revision.
Changing the item ID results in changing entire system history
Rev changes require creation of new ID and BOM update
BOM changes are labor intensive
BOM changes must occur individually and manually each time a part undergoes revision
Variances are not allowed
Cannot swap parts or revisions for a variance BOM, a complete new BOM must be created and all traveler paperwork reprinted
When moving to a new revision, the old revision must remain in the BOM until consumed which results in Sage reporting the need to purchase the old revision instead of the new revision.
Revision changeover must be manually watched and switched at point of consumption
Sage has a field for “Preferred Vendor ID”, but no additional approved suppliers
Single currency only
Sage50 has updates that come out every year, but they only support the previous years version for another 6 months so you're forced into an upgrade if want any semblance of support (though it doesn't really count as support most of the time).