How to replace (or Plid is null) with any thing more best practice?

Question

I work on SQL server 2012 I face issue I need to remove statement ( plid is null or ) with anything more good performance.

I enter CodeType Mandatory but plid not mandatory meaning maybe I entered or not

so main problem on my script using (or Plid is null)

I need to give anything alternative to (or Plid is null)

because it make query more slow

so what I do please

this is dashboard display count for Parts based on PLID and CodeTypeId

 

this is the full script 

CREATE TABLE #TempPlAndCodeType
 (
 CodeType NVARCHAR(100),
 PlName NVARCHAR(100),
 CodeTypeId int,
 PLID   int,
 [Status] Nvarchar(500)
 )

 create clustered index idx on #TempPlAndCodeType (CodeTypeId)
     insert into #TempPlAndCodeType(CodeType,PLID) values ('HTS-US',NULL)
    update c set c.CodeTypeId=a.AcceptedValuesOptionID from #TempPlAndCodeType c
    inner join Nop_AcceptedValuesOption a with (nolock) on
 a.Name = c.CodeType and AcceptedValuesID=5652
   update c set c.PLID=a.AcceptedValuesOptionID from #TempPlAndCodeType c
    inner join Nop_AcceptedValuesOption a with (nolock) on
 a.Name = c.PlName and AcceptedValuesID=110

 create table #AllPlData
 (
 PLID  nvarchar(50),
 PlIDName  nvarchar(500),
 PartFamilyId  int,
 PartId  int,
 CodeType nvarchar(50),
 CodeTypeId int
 )

 insert into #AllPlData(PLID,PlIDName,PartFamilyId,PartId)
 SELECT fmat.Value as PLID,acc.Name,fmat.PartFamilyID,pt.PartId

 FROM
 Parts.Nop_Part pt WITH(NOLOCK)
 INNER JOIN Parts.Nop_PartsFamilyAttribute fmat WITH(NOLOCK) ON  fmat.PartFamilyID=pt.PartsFamilyID AND fmat.[Key]=20281007
 INNER JOIN dbo.Nop_AcceptedValuesOption acc WITH(NOLOCK) ON acc.AcceptedValuesOptionID=fmat.Value

 create table #CountAllPartsPLs
 (
  PLID nvarchar(50),
  CountAllPLParts  int,
  Pl  nvarchar(500),
  CodeType  nvarchar(50),
  CodeTypeId  int
 )
 insert into #CountAllPartsPLs (PLID,CountAllPLParts)
 SELECT d.PLID,COUNT(d.PartID) AS CountAllPLParts
 FROM
 #AllPlData d
 inner join #TempPlAndCodeType c on c.PLID is null OR d.PLID=c.PLID
 GROUP BY d.PLID

 update p set p.Pl=d.PlIDName from #CountAllPartsPLs p inner join #AllPlData d on d.PLID = P.PLID

 select distinct t.PartId,c.CodeTypeId,c.CodeType,c.PlID,C.PlName,PartLevel into #tradecodes from parts.Tradecodes t
 inner join #TempPlAndCodeType c on t.CodeTypeId=c.CodeTypeId

 SELECT pt.PLID,tr.CodeTypeId,
 COUNT(pt.PartID) [#partsHasCodes]
 into #partsHasCodes
 FROM  #tradecodes tr WITH(NOLOCK)
 inner join #AllPlData pt  ON pt.PartID = tr.PartID
 WHERE (tr.PLID is null OR pt.PLID=tr.PLID)
 GROUP BY pt.PLID,tr.CodeTypeId

 SELECT s.PLID,c.CodeTypeId,
 sum(isnull(CountAllPLParts,0) - isnull([#partsHasCodes],0)) [#MissedpartsHasCodes] into #MissedpartsHasCodes
 FROM #CountAllPartsPLs s left join  #partsHasCodes c on c.PLID=s.PLID
 GROUP BY s.PLID,c.CodeTypeId

 ---------------------------
 SELECT pt.PLID,pt.CodeTypeId,
 COUNT(c.PartID ) AS [#partLevel]
 into #TpartLevel
 FROM #partsHasCodes pt
 inner join parts.TradeCodes c on c.CodeTypeId=pt.CodeTypeid and
 where c.PartLevel=1
 GROUP BY pt.PLID,pt.CodeTypeId
 ------------------------------

 SELECT s.PLID,c.CodeTypeId,
 sum(isnull([#partsHasCodes],0) - isnull([#partLevel],0)) [#partGeneration] into #TpartGeneration
 FROM #partsHasCodes s left join  #TpartLevel c on c.PLID=s.PLID --and c.CodeTypeid=s.CodeTypeid
 GROUP BY s.PLID,c.CodeTypeId

 SELECT  pt.PLID,t.CodeType
 into #AllPLs
 FROM
  #TempPlAndCodeType t
 inner join #AllPlData pt  on (t.PLID is null OR pt.PLID=t.PLID)
 left join Parts.TradeCodes tr WITH(NOLOCK) ON pt.PartID = tr.PartID
 left join #TempPlAndCodeType c on (c.CodeTypeId=tr.CodeTypeID)
 GROUP BY pt.PlIDName,t.CodeType,pt.PLID

 select L.CodeType,ca.Pl,isnull(Ca.CountAllPLParts,0) as PlPartCount,isnull(c.[#partsHasCodes],0) as PartsHaveCodes,ISNULL(m.[#MissedpartsHasCodes],0) as MissedParts ,isnull(G.[#partGeneration],0) PartsHaveGeneration,isnull(P.[#partLevel],0)PartsOnPartLevel
 from #AllPLs L
 left join #CountAllPartsPLs Ca on L.PLID=Ca.PLID
 left join #partsHasCodes C on L.PLID=c.PLID
 left join #MissedpartsHasCodes m on L.PLID=m.PLID
 left join #TpartGeneration G on G.PLID=C.PLID
 left join #TpartLevel P on P.PLID=C.PLID

 drop table #partsHasCodes
 drop table #TpartGeneration
 drop table #TpartLevel
 drop table #MissedpartsHasCodes
 drop table #TempPlAndCodeType
 drop table #AllPLs
 drop table #CountAllPartsPLs
 drop table #AllPlData
 drop table #tradecodes
 drop table #TempPlAndCodeType