SQL Server – Simple insertion instructions take so long

I have a scenario where a main stored procedure calls a nested procedure, and this nested procedure contains simple insert statements for multiple tables, and almost every insertion takes so long

I know that there are many possibilities, for example disk, processor, memory, indexes and triggers

How do I find that clustered and non-clustered indexes are not the cause of this slowness?

Insert a declaration:

INSERT IN PEDetail with (rowLock) (CID, CustID, PpeID, PeID, SubSys1ID, SubSys2ID, CharacteristicID, cmbID, PETemplateID).
SELECT CID, @ PID, @PpeID, PeID, SubSys1ID, SubSys2ID, CharacteristicID, cmbID, PETemplateID
DEPEDetail with (nolock)
where PpeID = @OldPpeid      

Table structure:

    SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE THE TABLE [dbo].[PEDetail](
    [CID] [int]    NOT NULL,
    [CustID] [int]    NOT NULL,
    [PpeID] [int]    NOT NULL,
    [PeID] [int]    NOT NULL,
    [SubSys1ID] [int]    NOT NULL,
    [SubSys2ID] [int]    NOT NULL,
    [CharacteristicID] [int]    NOT NULL,
    [cmbID] [int]    NOT NULL,
    [PETemplateID] [int]    NOT NULL,
CONSTRAINT [PK_PEDetail] CLUSTERED PRIMARY KEY
(
    [CID] ASC
    [CustID] ASC
    [PpeID] ASC
    [PeID] ASC
    [SubSys1ID] ASC
    [SubSys2ID] ASC
    [CharacteristicID] ASC
    [cmbID] ASC
    [PETemplateID] ASC
) WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) SURE [PRIMARY]

GO

ALTER TABLE [dbo].[PEDetail]  WITH VERIFY ADD CONSTRAINT [FK_PEDetail_PEHeader] FOREIGN KEY ([PpeID], [PeID])
REFERENCES [dbo].[PEHeader] ([PpeID], [PeID])
GO

ALTER TABLE [dbo].[PEDetail] CHECK OF CONSTRAINT [FK_PEDetail_PEHeader]
GO

ALTER TABLE [dbo].[PEDetail] ADD CONSTRAINT [DF_PEDetail_cmbID]  DEFAULT ((0)) FOR [cmbID]
GO

Nonclustered indexes:

CREATE A NON CLUSTERED INDEX [ix_PEDetail_CID_PeID_6] SURE [dbo].[PEDetail] 
(
    [CID] ASC
    [PeID] ASC
    [SubSys1ID] ASC
    [SubSys2ID] ASC
    [CharacteristicID] ASC
    [PETemplateID] ASC
) WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_POUR_LOGKS = ON, ALLOW_POUR_LOGKS = ON, ALLOW_PAGE_L, = ON, FILLFACTOR = 90). [PRIMARY]
GO



CREATE A NON CLUSTERED INDEX [IX_CID_CharacteristicID_CID_CharacteristicID] SURE [dbo].[PEDetail] 
(
    [CID] ASC
    [CharacteristicID] ASC
)
UNDERSTAND ( [PpeID]) WITH (PAD_INDEX = OFF, OFFSET_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF 85) [PRIMARY]
GO


CREATE A NON CLUSTERED INDEX [IX_PpeID_PeID] SURE [dbo].[PEDetail] 
(
    [PpeID] ASC
    [PeID] ASC
)
UNDERSTAND ( [CID],
[CustID],
[SubSys1ID],
[SubSys2ID],
[CharacteristicID],
[cmbID],
[PETemplateID]) WITH (PAD_INDEX = OFF, OFFSET_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF 85) [PRIMARY]
GO