[Internal} Diseconomies of scale is when per-unit costs increase which occurs when a firm/company grows too big - it starts to get 'out of hand/control' -- e.g. Too many staff, may be hard to manage them all (Managerial) - and may have problems communicating / co-operating, etc.
Examples of external diseconomies of scale may be that OTHER firms come into the market, taking advantage of the 'potential' your firm has built up in that area (e.g. "Oh, the computers in USA are very good in quality ! (假如)" -- then a new firm comes into market - gaining advantage on that )
Examples of external diseconomies of scale may be that OTHER firms come into the market, taking advantage of the 'potential' your firm has built up in that area (e.g. "Oh, the computers in USA are very good in quality ! (假如)" -- then a new firm comes into market - gaining advantage on that )