This is a complex one. SAP usually does not allow you to delete anything. You will have to archive and then delete the objects. If there are "bad" projects without any transactional activity, you can mark the projects with status DLFL. To archive, use transaction code SARA.
You will have to get your entire functional team - MM, SD, FI, CO, PS - and decide on a module-by-module and transaction-by-transaction basis on the best approach to purge this data. You will also have to think about auditing and retrieval if this is production data.
Solution is Archiving. It's a seperate process better consult you basis consultants for this.
Archiving object you should be looking at is PS_PROJECT (T Code SARA)
T-Codes List Used In SAP-PS For Customization Part 2
OPA0 Status selection profiles
OPA1 Maintain combination definitions
OPA2 Define selection profile
OPA3 Define option profile
OPA4 Define list profile
OPA5 Define graphics profile
OPA6 Define overall profile
OPA7 Define columns
OPA9 Maintain selection profiles
OPB1 Define list versions
OPB2 Define distribution function
OPB3 Specify distribution functions
OPB4 Specify distribution strategies
OPB5 Specify distribution key
OPC0 Axis representation selection
OPC1 Maintain axis representation
OPC2 Curve representation selection
OPC3 Maintain curve representation
OPC5 Max. no. of data records
OPCD Capacity category
OPCE Capacity planner
OPCF Time units
OPCG Maintain Operation Control Key
OPCH Maintain production scheduler
OPCI Setup group key/category
OPCL Scheduling type
OPCM Standard value key
OPCN Maintain move time matrix
OPCQ Efficiency rate
OPCR Formula parameters
OPCS Define formula
OPCT Strategies
OPCU Strategy levels
OPCW Planned order parameters
OPCX Formula parameters
OPCY Define formula
OPD0 Resource planning overall profile
OPD1 Resource planning selection profile
OPD2 Capacity leveling - time profile
OPD3 Resource planning evaluation profile
OPD4 Resource planning period profile
OPD5 Flow control definition
OPD6 Flow control control table
OPD7 Flow control statuses
OPD8 Flow Control Actions
OPD9 Flow Control Messages
OPDA Transition matrix (setup matrix)
OPDB Capacity Leveling Strategy Profile
OPDD Factory calendar
OPDE Resource planning control profile
OPDF Define requirements grouping
OPDH Capacity leveling - list profile
OPDJ Define layout
OPDK Define standard overview
OPDL Cap. plan. detailed cap.list maint.
OPDM Define detail list (leveling)
OPDQ Profile for planning table (tab.)
OPDR Define layout key
OPDT Define detail list
OPDU Maintain perf. efficiency rate
key
OPDV Com-file (Rel-Info/OLPK) KOP.
Set´s
OPDW Com-file (Rel-Info/OLPK) KOP.
Set´s
OPE0 Maintain Sort String
OPE1 Maintain Value Type
OPE2 Maintain Machine Type
OPE3 Maintain Planner Group
OPE4 Maintain Control Parameters
OPE5 Maintain rounding categories
OPE6 Maintain Rounding Category
OPE7 Maintain overhead key
OPE8 Maint. Roundg. and Add.Val.Key
(Def)
OPE9 Maintain User Profile
OPEA User selection
OPEB Automatic selection
OPEC PP user fields
OPENPS Download Activities to Palm Pilot
OPF0 Maintain User
OPF1 Authorizations for CAPP
OPFA Field selection: Work center
OPFP Configuring the Fixed Price Version
OPFR01 RPUCORF0PBS : IMG Link
OPG0 Profile for planning table
OPG1 Chart sequence - selection
OPG2 Line representation
OPG3 Scale time axis
OPG4 Time scale profile
OPG5 Graphic obj.type sel./repr.profile
OPG6 Transition matrix setup fam.key
OPG7 Line display selection
OPG9 Graphical object type/obj.represent.
OPGD Ref. Oper. Set-All Task Lists
(PP)
OPGE Ref. Oper. Set - Rate Routings
(PP)
OPGF Work Center - All Task Lists (PP)
OPGG Work Center - Rate Routings (PP)
OPGH Document PRT - All Task Lists
OPGI Equipment PRT - All Task Lists
OPGJ Material PRT - All Task Lists
OPGK Misc. PRT - All Task Lists
OPGL Resource - Master Recipes (PI)
OPGM Process Instr. Cat. - Master Recipe
OPGN Document PRT - Maintenance Task
List
OPGO Equipment PRT-Maintenance Task
Lists
OPGP Material PRT - Maintenance Task
List
OPGQ Misc. PRT - Maintenance Task Lists
OPGR Work Center - Standard Network
(PS)
OPGS Document PRT - Standard Network
(PS)
OPGT Equipment PRT - Standard Network(PS)
OPGU Material PRT - Standard Network
(PS)
OPGV Misc. PRT - Standard Network (PS)
OPH1 CO Cash Bgt Mgmt: Delete Actual
Data
OPH2 PS Cash Management: Delete Plan
Data
OPH3 CO Cash Bgt Mgmt: Delete Master
Data
OPH4 CO Cash Bgt Mgmt: MM Data Transfer
OPH5 CO CBM: Successive FI Data Transfer
OPH6 CO CBM: Take Over FI Completely
OPH7 CO-CBM: Take Over All Data
OPI1 Maintain Value Categories
OPI2 Value Categories for Cost Elements
OPI3 Update Control: File RPSCO
OPI4 Commitment Item Value Categories
OPI5 Value Categories for Stag.Key
Figs
OPI6 Activate CO Cash Budget Management
OPI8 Display Value Category
OPIA Interest Profile for Projects
OPIB Maintain Interest Profile
OPIC Intrst Relevance: Cost Els/Cmmt
Itms
OPID Proj.Int Calc: Account Determination
OPIE Interest Indicator
OPIF View Maintenance:Compound Int.Cont.
OPIG View Maint.: Compound Int. Periods
OPIH Interest Scale, General Conditions
OPIN Number range maintnce: VHU_PINST
OPJ2 Production order stock determination
OPJ4 Schedule batch function request
OPJ6 Maintain Status Profiles
OPJ7 Maintain Routing Usage
OPJ8 Maintain Operation Control Key
OPJ9 Maintain prod. scheduler group
OPJA Maintain setup group/group category
OPJB Specify system messages
OPJC Maintain Wage Groups
OPJD Item Categories
OPJE User Selection
OPJF Automatic Selection
OPJG Maintain Default Values
OPJH Order types production order
OPJI BOM Usage Priorities
OPJJ Maintain Scope of Check
OPJK Maintain Control
OPJL Maintain Checking Rule
OPJM Application-Specific Criteria
OPJN Maintain Scheduling Type
OPJO C MM-BD units of measurement
OPJP Maint. acct.assgnm.types for orders
OPJQ Standard Value Key
OPJR Maintain move time matrix
OPJS PP: Maintain reduction strategies
OPJT Maintain Strategy Levels
OPJU Production order control parameters
OPJV Maintain Capacity Category
OPJW Maintain Capa.Planr.Grp for WrkCentr
OPJX Factory Calendar C
OPJY Maintain perf. efficiency rate
key
OPJZ Maintain Release Periods
OPK0 Confirmation Parameters PP
OPK0T Confirmation Parameters
OPK1 Confirmation Parameters PP-PI
OPK1T Confirmation Parameters
OPK2 Formula Parameters
OPK3 Define Formula
OPK4 Confirmation Parameters
OPK5 Maintain variances
OPK6 List Layout
OPK7 Accessing Customizing PDC transfer
OPK8 Maintain print control prod. orders
OPK9 Maintain Goods Receipt Valuation
OPKA Maintain Movement Types
OPKB Control parallel confirmation
OPKC Control confirmation process chain
OPKD Control confirmation process chain
OPKE Screen Sequence for Components
OPKF Control parallel confirmation
OPKG Maintain Messages
OPKH Maintain Breakpoints
OPKI Maintain Collective Confirmation
OPKJ Maintain PRT Control Key
OPKK Standard Text
OPKL Formula Parameters
OPKM Define Formula
OPKN Overview variant production control
OPKO Command File for Production Orders
OPKP Shop floor control profile
OPKQ Customizing: Matchcode for Proc.Ord.
OPKR Print flag
OPKS Maintain Origins for CO Object
OPKT Initial Screen: Settlement Structure
OPKU Maintain Collective Confirmation
OPKV Print Flag
OPKW Print shop papers
OPKX Deletion Flag/Indicator
OPKZ Customizing Matchcode for ProdOrder
OPL1 Costing Variants: PP Prod. Order
OPL2 Maintain trigger point group
OPL3 Trigger point usage
OPL4 Profile for missing parts list
OPL5 Order type LIS parameters
OPL6 Profile for documented goods mvmts
OPL7 Order change management profile
OPL8 Order type parameters: Overview
OPL9 Parameters for order change mgmt
OPLA Conditions: V_T682F for H CO
OPLB CondTab: Create (batch, prod.)
OPLC CondTab: Change (batchs, prod.)
OPLD CondTab: Display (batches, prod.)
OPLE Strategy types: Batch determ.
(prod)
OPLF Access: Maintain batch determ.(prod)
OPLG Batch determ.: Procedure for prod.
OPLH Overview variant - production
orders
OPLI Background job for goods movements
OPLJ Job "Fast entry confirmation"
OPLK Overall profile for order prog.
rep.
OPLL Order progress: Displayed fields
OPLM Order progress: Displayed fields
OPLO maintain selection profile
OPLP Job "Convert planned order"
OPLQ maintain filter for control keys
OPLR Maintain filter for capacity version
OPLS Parallel processing control
OPLT Target System for Data Transfer
OPLV Maintain Filter for Task List
Usage
OPLW Maintain Filter for Task List
Status
OPLX Maintain Filter for BOM Usage
OPLY Maintain Filter for BOM Status
OPLZ Maintain POI Planned Order Selection
OPM0 Maintain profile - field selection
OPM1 Costing Variants - Production
Order
OPM2 Maintain Detail Screen Control
Oper.
OPM3 Maintain Detail Scrn Control Header
OPMF Field Selection - BOM Transfer
OPMI Import models activities
OPMJ Determine progress values
