The business risk is that PPE could be potentially overstated and key assertion was valuation & allocation. This is due to the fact that the reject shop has closed down few of their shops due to poor profitability and hence not disclosed or written off the amounts. Or

Depreciation understated- scrapped some of fixture and fitting

Wrong professional judgement with useful life of PPE- lead to calculation error, therefore PPE could be overstated

this is what I have found and I need to gather evidence of the fact that PPE is overstated and such.